http://www.lahc.edu/math/precalculus/math_260a.html
Polar Coordinates
Polar Coordinates
The location of a point P in the plane may be given
by the following two numbers:
P
x
y
(r, )
O
Polar Coordinates
r = the distance between P and the origin O(0, 0)
The location of a point P in the plane may be given
by the following two numbers:
P
x
(r, )
r
O
y
Polar Coordinates
r = the distance between P and the origin O(0, 0)
 = a signed angle between the positive x–axis and
the direction to P,
The location of a point P in the plane may be given
by the following two numbers:
P
x
(r, )

r
O
y
Polar Coordinates
r = the distance between P and the origin O(0, 0)
 = a signed angle between the positive x–axis and
the direction to P, specifically,
 is + for counter clockwise measurements and
 is – for clockwise measurements.
The location of a point P in the plane may be given
by the following two numbers:
P
x
(r, )

r
O
y
Polar Coordinates
r = the distance between P and the origin O(0, 0)
 = a signed angle between the positive x–axis and
the direction to P, specifically,
 is + for counter clockwise measurements and
 is – for clockwise measurements.
The location of a point P in the plane may be given
by the following two numbers:
The ordered pair (r, ) is a polar coordinate of P.
P
x
(r, )

r
O
y
Polar Coordinates
r = the distance between P and the origin O(0, 0)
 = a signed angle between the positive x–axis and
the direction to P, specifically,
 is + for counter clockwise measurements and
 is – for clockwise measurements.
The location of a point P in the plane may be given
by the following two numbers:
The ordered pair (r, ) is a polar coordinate of P.
P
x
(r, )

r
The ordered pairs (r,  ±2nπ ) with
n = 0,1, 2, 3… give the same
geometric information hence lead to
the same location P(r, ).
O
y
Polar Coordinates
r = the distance between P and the origin O(0, 0)
 = a signed angle between the positive x–axis and
the direction to P, specifically,
 is + for counter clockwise measurements and
 is – for clockwise measurements.
The location of a point P in the plane may be given
by the following two numbers:
The ordered pair (r, ) is a polar coordinate of P.
P
x
(r, )

r
The ordered pairs (r,  ±2nπ ) with
n = 0,1, 2, 3… give the same
geometric information hence lead to
the same location P(r, ).
We also use signed distance,
i.e. with negative values of r which
means we are to step backward for
a distance of lrl. O
y
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Polar Coordinates
Conversion Rules
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
O
The rectangular and polar
coordinates relations
x =
y =
r =
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
O x = r*cos()
The rectangular and polar
coordinates relations
x = r*cos()
y = r*sin()
y = r*sin()
r =
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
O x = r*cos()
y = r*sin()
The rectangular and polar
coordinates relations
x = r*cos()
y = r*sin()
r = √ x2 + y2
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
O x = r*cos()
y = r*sin()
The rectangular and polar
coordinates relations
x = r*cos()
y = r*sin()
r = √ x2 + y2
For  we have
tan() =
cos() =
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
x = r*cos()
y = r*sin()
The rectangular and polar
coordinates relations
x = r*cos()
y = r*sin()
r = √ x2 + y2
For  we have
tan() = y/x
cos() = x/√x2 + y2
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Conversion Rules
Let (x, y)R and (r, )P be the rectangular and polar
coordinates of the same point P, then
P
x
y
(r, )R = (x, y)P

r
O x = r*cos()
y = r*sin()
The rectangular and polar
coordinates relations
x = r*cos()
y = r*sin()
r = √ x2 + y2
For  we have
 = tan–1(y/x)
 = cos–1 (x/√x2 + y2)
tan() = y/x
cos() = x/√x2 + y2
inverse trig. functions that
or using
If needed, we write (a, b)P for a polar coordinate
ordered pair, and (a, b)R for the rectangular
coordinate ordered pair.
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
x = r*cos()
y = r*sin()
r2 = x2 + y2
tan() = y/x
For A(4, 60o)P
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
x = r*cos()
y = r*sin()
A(4, 60o)P
r2 = x2 + y2
tan() = y/x
For A(4, 60o)P
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
r2 = x2 + y2
tan() = y/x
x
y
60o
4
A(4, 60o)P
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
r2 = x2 + y2
tan() = y/x
x
y
60o
4
A(4, 60o)P
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
r2 = x2 + y2
tan() = y/x
x
y
60o
4
A(4, 60o)P
B(5, 0)P
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
A(4, 60o)P
B(5, 0)P
4
r2 = x2 + y2
tan() = y/x
–45o
C
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
A(4, 60o)P
B(5, 0)P
4
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
A(4, 60o)P
B(5, 0)P
4
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C&D
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
A(4, 60o)P
B(5, 0)P
C(4, –45o)P
= D(–4, 3π/4 rad)P
4
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C&D
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
(x, y)R = (4cos(–45), 4sin(–45))
= (–4cos(3π/4), –4sin(3π/4))
A(4, 60o)P
B(5, 0)P
C(4, –45o)P
= D(–4, 3π/4 rad)P
4
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C&D
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
(x, y)R = (4cos(–45), 4sin(–45))
= (–4cos(3π/4), –4sin(3π/4))
= (22, –22)
A(4, 60o)P
B(5, 0)P
C(4, –45o)P
= D(–4, 3π/4 rad)P
4
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C&D
Polar Coordinates
Example A. a. Plot the following polar coordinates
A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P.
Find their corresponding rectangular coordinates.
x
y
60o
4
For A(4, 60o)P
x = r*cos()
y = r*sin()
(x, y)R = (4*cos(60), 4*sin(60)),
= (2, 23)
for B(5, 0o)P, (x, y) = (5, 0),
for C and D,
(x, y)R = (4cos(–45), 4sin(–45))
= (–4cos(3π/4), –4sin(3π/4))
= (22, –22)
A(4, 60o)P
B(5, 0)P
C(4, –45o)P
= D(–4, 3π/4 rad)P
4
Converting rectangular positions
into polar coordinates requires
more care.
r2 = x2 + y2
tan() = y/x
–45o
3π/4
C&D
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
x
y
E(–4, 3)
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
x
y
E(–4, 3)
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
x
y
E(–4, 3)
r=5
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
There is no single formula that
would give .
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
x
y
E(–4, 3)
r=5

Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
There is no single formula that
would give . This is because  has
to be expressed via the inverse
trig–functions hence the position of
E dictates which inverse function
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
would be easier to use to extract .
x
y
E(–4, 3)
r=5

Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
would be easier to use to extract . Since E is in the
2nd quadrant, the angle  may be recovered by the
cosine inverse function (why?).
x
y
E(–4, 3)
r=5
There is no single formula that
would give . This is because  has
to be expressed via the inverse
trig–functions hence the position of
E dictates which inverse function

Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
x
y
E(–4, 3)

r=5
would be easier to use to extract . Since E is in the
2nd quadrant, the angle  may be recovered by the
cosine inverse function (why?). So  = cos–1(–4/5) ≈
143o
There is no single formula that
would give . This is because  has
to be expressed via the inverse
trig–functions hence the position of
E dictates which inverse function
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
x
y
E(–4, 3)

r=5
would be easier to use to extract . Since E is in the
2nd quadrant, the angle  may be recovered by the
cosine inverse function (why?). So  = cos–1(–4/5) ≈
143o or that E(–4, 3)R ≈ (5,143o)P
There is no single formula that
would give . This is because  has
to be expressed via the inverse
trig–functions hence the position of
E dictates which inverse function
Polar Coordinates
b. Find a polar coordinate then list all possible polar
coordinates for each of the following points
(with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
We have the distance formula r = x2 + y2,
hence for E, r = 16 + 9 = 5.
x
y
E(–4, 3)

r=5
would be easier to use to extract . Since E is in the
2nd quadrant, the angle  may be recovered by the
cosine inverse function (why?). So  = cos–1(–4/5) ≈
143o or that E(–4, 3)R ≈ (5,143o)P = (5,143o±n*360o)P
There is no single formula that
would give . This is because  has
to be expressed via the inverse
trig–functions hence the position of
E dictates which inverse function
Polar Coordinates
For F(3, –2)R,
x
y
F(3, –2,)
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)
r=√13
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function.

r=√13
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
the advantage of obtaining the answer directly from
the x and y coordinates.

r=√13
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
the advantage of obtaining the answer directly from
the x and y coordinates. So  = tan–1(–2/3)
≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P

r=√13
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)

r=√13
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
= (√13, –0.588rad ± 2nπ)P
the advantage of obtaining the answer directly from
the x and y coordinates. So  = tan–1(–2/3)
≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)

r=√13
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
= (√13, –0.588rad ± 2nπ)P
the advantage of obtaining the answer directly from
the x and y coordinates. So  = tan–1(–2/3)
≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P
For G(–3, –1)R, r = 9 + 1 = √10.
x
y
G(–3, –1)
r=√10
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)

r=√13
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
= (√13, –0.588rad ± 2nπ)P
the advantage of obtaining the answer directly from
the x and y coordinates. So  = tan–1(–2/3)
≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P
For G(–3, –1)R, r = 9 + 1 = √10.
G is the 3rd quadrant. Hence  can’t
be obtained directly via the inverse–
trig functions.
x
y
G(–3, –1)
r=√10
Polar Coordinates
For F(3, –2)R, r = 9 + 4 = √13.
x
y
F(3, –2,)

r=√13
Since F is in the 4th quadrant, the
angle  may be recovered by the
sine inverse or the tangent inverse
function. The tangent inverse has
= (√13, –0.588rad ± 2nπ)P
the advantage of obtaining the answer directly from
the x and y coordinates. So  = tan–1(–2/3)
≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P
For G(–3, –1)R, r = 9 + 1 = √10.
G is the 3rd quadrant. Hence  can’t
be obtained directly via the inverse–
trig functions. We will find the angle
A as shown first, then  = A + π.
x
y
G(–3, –1)
r=√10
A
Polar Coordinates
Again, using tangent inverse
A = tan–1(1/3) ≈ 18.3o
x
y
G(–3, –1)
r=√10
A
Polar Coordinates
Again, using tangent inverse
A = tan–1(1/3) ≈ 18.3o so
 = 180 + 18.3o = 198.3o
x
y
G(–3, –1)
r=√10
A

Polar Coordinates
Again, using tangent inverse
A = tan–1(1/3) ≈ 18.3o so
 = 180 + 18.3o = 198.3o or
G ≈ (√10, 198.3o ± n x 360o)P
x
y
G(–3, –1)
r=√10
A

HW
Pg 367 3-21 all

t6 polar coordinates

  • 1.
  • 2.
    Polar Coordinates The locationof a point P in the plane may be given by the following two numbers: P x y (r, ) O
  • 3.
    Polar Coordinates r =the distance between P and the origin O(0, 0) The location of a point P in the plane may be given by the following two numbers: P x (r, ) r O y
  • 4.
    Polar Coordinates r =the distance between P and the origin O(0, 0)  = a signed angle between the positive x–axis and the direction to P, The location of a point P in the plane may be given by the following two numbers: P x (r, )  r O y
  • 5.
    Polar Coordinates r =the distance between P and the origin O(0, 0)  = a signed angle between the positive x–axis and the direction to P, specifically,  is + for counter clockwise measurements and  is – for clockwise measurements. The location of a point P in the plane may be given by the following two numbers: P x (r, )  r O y
  • 6.
    Polar Coordinates r =the distance between P and the origin O(0, 0)  = a signed angle between the positive x–axis and the direction to P, specifically,  is + for counter clockwise measurements and  is – for clockwise measurements. The location of a point P in the plane may be given by the following two numbers: The ordered pair (r, ) is a polar coordinate of P. P x (r, )  r O y
  • 7.
    Polar Coordinates r =the distance between P and the origin O(0, 0)  = a signed angle between the positive x–axis and the direction to P, specifically,  is + for counter clockwise measurements and  is – for clockwise measurements. The location of a point P in the plane may be given by the following two numbers: The ordered pair (r, ) is a polar coordinate of P. P x (r, )  r The ordered pairs (r,  ±2nπ ) with n = 0,1, 2, 3… give the same geometric information hence lead to the same location P(r, ). O y
  • 8.
    Polar Coordinates r =the distance between P and the origin O(0, 0)  = a signed angle between the positive x–axis and the direction to P, specifically,  is + for counter clockwise measurements and  is – for clockwise measurements. The location of a point P in the plane may be given by the following two numbers: The ordered pair (r, ) is a polar coordinate of P. P x (r, )  r The ordered pairs (r,  ±2nπ ) with n = 0,1, 2, 3… give the same geometric information hence lead to the same location P(r, ). We also use signed distance, i.e. with negative values of r which means we are to step backward for a distance of lrl. O y
  • 9.
    If needed, wewrite (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair. Polar Coordinates
  • 10.
    Polar Coordinates Conversion Rules Ifneeded, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 11.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r O The rectangular and polar coordinates relations x = y = r = If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 12.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r O x = r*cos() The rectangular and polar coordinates relations x = r*cos() y = r*sin() y = r*sin() r = If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 13.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r O x = r*cos() y = r*sin() The rectangular and polar coordinates relations x = r*cos() y = r*sin() r = √ x2 + y2 If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 14.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r O x = r*cos() y = r*sin() The rectangular and polar coordinates relations x = r*cos() y = r*sin() r = √ x2 + y2 For  we have tan() = cos() = If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 15.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r x = r*cos() y = r*sin() The rectangular and polar coordinates relations x = r*cos() y = r*sin() r = √ x2 + y2 For  we have tan() = y/x cos() = x/√x2 + y2 If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 16.
    Polar Coordinates Conversion Rules Let(x, y)R and (r, )P be the rectangular and polar coordinates of the same point P, then P x y (r, )R = (x, y)P  r O x = r*cos() y = r*sin() The rectangular and polar coordinates relations x = r*cos() y = r*sin() r = √ x2 + y2 For  we have  = tan–1(y/x)  = cos–1 (x/√x2 + y2) tan() = y/x cos() = x/√x2 + y2 inverse trig. functions that or using If needed, we write (a, b)P for a polar coordinate ordered pair, and (a, b)R for the rectangular coordinate ordered pair.
  • 17.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates.
  • 18.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y x = r*cos() y = r*sin() r2 = x2 + y2 tan() = y/x For A(4, 60o)P
  • 19.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 x = r*cos() y = r*sin() A(4, 60o)P r2 = x2 + y2 tan() = y/x For A(4, 60o)P
  • 20.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), r2 = x2 + y2 tan() = y/x x y 60o 4 A(4, 60o)P
  • 21.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) r2 = x2 + y2 tan() = y/x x y 60o 4 A(4, 60o)P
  • 22.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), r2 = x2 + y2 tan() = y/x x y 60o 4 A(4, 60o)P B(5, 0)P
  • 23.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, A(4, 60o)P B(5, 0)P 4 r2 = x2 + y2 tan() = y/x –45o C
  • 24.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, A(4, 60o)P B(5, 0)P 4 r2 = x2 + y2 tan() = y/x –45o 3π/4 C
  • 25.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, A(4, 60o)P B(5, 0)P 4 r2 = x2 + y2 tan() = y/x –45o 3π/4 C&D
  • 26.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, A(4, 60o)P B(5, 0)P C(4, –45o)P = D(–4, 3π/4 rad)P 4 r2 = x2 + y2 tan() = y/x –45o 3π/4 C&D
  • 27.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, (x, y)R = (4cos(–45), 4sin(–45)) = (–4cos(3π/4), –4sin(3π/4)) A(4, 60o)P B(5, 0)P C(4, –45o)P = D(–4, 3π/4 rad)P 4 r2 = x2 + y2 tan() = y/x –45o 3π/4 C&D
  • 28.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, (x, y)R = (4cos(–45), 4sin(–45)) = (–4cos(3π/4), –4sin(3π/4)) = (22, –22) A(4, 60o)P B(5, 0)P C(4, –45o)P = D(–4, 3π/4 rad)P 4 r2 = x2 + y2 tan() = y/x –45o 3π/4 C&D
  • 29.
    Polar Coordinates Example A.a. Plot the following polar coordinates A(4, 60o)P , B(5, 0o)P, C(4, –45o)P, D(–4, 3π/4 rad)P. Find their corresponding rectangular coordinates. x y 60o 4 For A(4, 60o)P x = r*cos() y = r*sin() (x, y)R = (4*cos(60), 4*sin(60)), = (2, 23) for B(5, 0o)P, (x, y) = (5, 0), for C and D, (x, y)R = (4cos(–45), 4sin(–45)) = (–4cos(3π/4), –4sin(3π/4)) = (22, –22) A(4, 60o)P B(5, 0)P C(4, –45o)P = D(–4, 3π/4 rad)P 4 Converting rectangular positions into polar coordinates requires more care. r2 = x2 + y2 tan() = y/x –45o 3π/4 C&D
  • 30.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R.
  • 31.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. x y E(–4, 3)
  • 32.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, x y E(–4, 3)
  • 33.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. x y E(–4, 3) r=5
  • 34.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. There is no single formula that would give . We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. x y E(–4, 3) r=5 
  • 35.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. There is no single formula that would give . This is because  has to be expressed via the inverse trig–functions hence the position of E dictates which inverse function We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. would be easier to use to extract . x y E(–4, 3) r=5 
  • 36.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. would be easier to use to extract . Since E is in the 2nd quadrant, the angle  may be recovered by the cosine inverse function (why?). x y E(–4, 3) r=5 There is no single formula that would give . This is because  has to be expressed via the inverse trig–functions hence the position of E dictates which inverse function 
  • 37.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. x y E(–4, 3)  r=5 would be easier to use to extract . Since E is in the 2nd quadrant, the angle  may be recovered by the cosine inverse function (why?). So  = cos–1(–4/5) ≈ 143o There is no single formula that would give . This is because  has to be expressed via the inverse trig–functions hence the position of E dictates which inverse function
  • 38.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. x y E(–4, 3)  r=5 would be easier to use to extract . Since E is in the 2nd quadrant, the angle  may be recovered by the cosine inverse function (why?). So  = cos–1(–4/5) ≈ 143o or that E(–4, 3)R ≈ (5,143o)P There is no single formula that would give . This is because  has to be expressed via the inverse trig–functions hence the position of E dictates which inverse function
  • 39.
    Polar Coordinates b. Finda polar coordinate then list all possible polar coordinates for each of the following points (with r > 0): E(–4, 3)R, F(3, –2)R, and G(–3, –1)R. We have the distance formula r = x2 + y2, hence for E, r = 16 + 9 = 5. x y E(–4, 3)  r=5 would be easier to use to extract . Since E is in the 2nd quadrant, the angle  may be recovered by the cosine inverse function (why?). So  = cos–1(–4/5) ≈ 143o or that E(–4, 3)R ≈ (5,143o)P = (5,143o±n*360o)P There is no single formula that would give . This is because  has to be expressed via the inverse trig–functions hence the position of E dictates which inverse function
  • 40.
    Polar Coordinates For F(3,–2)R, x y F(3, –2,)
  • 41.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,) r=√13
  • 42.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,) Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function.  r=√13
  • 43.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,) Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has the advantage of obtaining the answer directly from the x and y coordinates.  r=√13
  • 44.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,) Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has the advantage of obtaining the answer directly from the x and y coordinates. So  = tan–1(–2/3) ≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P  r=√13
  • 45.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,)  r=√13 Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has = (√13, –0.588rad ± 2nπ)P the advantage of obtaining the answer directly from the x and y coordinates. So  = tan–1(–2/3) ≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P
  • 46.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,)  r=√13 Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has = (√13, –0.588rad ± 2nπ)P the advantage of obtaining the answer directly from the x and y coordinates. So  = tan–1(–2/3) ≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P For G(–3, –1)R, r = 9 + 1 = √10. x y G(–3, –1) r=√10
  • 47.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,)  r=√13 Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has = (√13, –0.588rad ± 2nπ)P the advantage of obtaining the answer directly from the x and y coordinates. So  = tan–1(–2/3) ≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P For G(–3, –1)R, r = 9 + 1 = √10. G is the 3rd quadrant. Hence  can’t be obtained directly via the inverse– trig functions. x y G(–3, –1) r=√10
  • 48.
    Polar Coordinates For F(3,–2)R, r = 9 + 4 = √13. x y F(3, –2,)  r=√13 Since F is in the 4th quadrant, the angle  may be recovered by the sine inverse or the tangent inverse function. The tangent inverse has = (√13, –0.588rad ± 2nπ)P the advantage of obtaining the answer directly from the x and y coordinates. So  = tan–1(–2/3) ≈ –0.588rad and that F(3, –2)R ≈ (√13, –0.588rad)P For G(–3, –1)R, r = 9 + 1 = √10. G is the 3rd quadrant. Hence  can’t be obtained directly via the inverse– trig functions. We will find the angle A as shown first, then  = A + π. x y G(–3, –1) r=√10 A
  • 49.
    Polar Coordinates Again, usingtangent inverse A = tan–1(1/3) ≈ 18.3o x y G(–3, –1) r=√10 A
  • 50.
    Polar Coordinates Again, usingtangent inverse A = tan–1(1/3) ≈ 18.3o so  = 180 + 18.3o = 198.3o x y G(–3, –1) r=√10 A 
  • 51.
    Polar Coordinates Again, usingtangent inverse A = tan–1(1/3) ≈ 18.3o so  = 180 + 18.3o = 198.3o or G ≈ (√10, 198.3o ± n x 360o)P x y G(–3, –1) r=√10 A 
  • 52.