Graphs of linear equation

Graphs of linear equation

• 1.
  GRAPHS OF LINEAREQUATION
• 2.
  WHAT IS ALINEAR EQUATION?  A linear equation is an equation whose graph forms a straight line.  Linear equations are usually shown on a coordinate plane  Real life situations of linear equations include the stock market as well as the payments of a car.
• 3.
  PARTS OF ACOORDINATE PLANE Origin Y-Axis X-Axis QUADRANT II (-x, y) QUADRANT I (x, y) QUADRANT III (-x, -y) QUADRANT IV (x, -y)
• 4.
  METHODS IN GRAPHINGA LINEAR EQUATION  Using two points  Using x- and –y intercepts  Using the slope and –y intercepts  Using the slope and a point
• 5.
  USING TWO POINTS Example: Graphthe function: y = 2x+1 X 0 1 Y 1 3 Substitution: y =2x+1 y= 2(0)+1 y= 1 y=2x+1 y=2(1)+1 y=3
• 6.
  4 (1,3) 3 2 (0,1) 1 -4 -3 -2-1 1 2 3 4 -1 -2 -3 -4
• 7.
  GRAPH THIS: 1. (3,4)and (1,2) 2. (0,5) and (6,1) 3. (-2, 5/2) and ( ½ , ¾)
• 8.
  USING X-INTERCEPT ANDY- INTERCEPT  A linear equation can be graphed by using x-intercept a and y-intercept b.  (a,0) and (0,b) are enough to graph linear equation.  X-intercept- the abscissa  Y-intercept- the ordinate b a
• 9.
  EXAMPLE:  y =3x+2 X 0 -2/3 Y 2 0 Tip: Using this method, you need to solve for x- intercept by letting y=0 and y-intercept by letting x=0 1 2 3 - 1 - 2 - 3 1 2 3 3 2 1
• 10.
  USING SLOPE ANDY-INTERCEPT  In using this method, you need to identify the slope and the y- intercept of the linear equation.  In equation y = 6x+2 m= 6 rise= 6 run= 1 y= 2
• 11.
  TRY THIS:  m=2/4 and b= 2  m= 1 and b= 3  y= ¾ x +3 y= ½x + 1
• 12.
  USING SLOPE ANDONE POINT  To find a point from any equation, assign any value for x in the given equation. Example: In equation y= 2x+1 slope: 2 ordered pair: (-1,-1) Let x= -1 y = -1
• 13.
  TRY THIS  m=3and (0,-5)  m = -3 and (2,4)  m= 2/3 and (-2,5)