import turtle # import the turtle module to draw the graph with

# set up the screen

wn = turtle.Screen()

# set up the turtle

graph = turtle.Turtle()

graph.hideturtle() # hide the turtle so the graph looks nice

graph.speed(0) # speed up the turtle

# draw the axes

# x axis

graph.forward(250)

graph.penup()

graph.goto(250,5)

graph.write('x',font=('Cambria',12,'italic'))

graph.goto(0,0)

graph.pendown()

graph.backward(250)

graph.forward(250)

# y axis

graph.left(90)

graph.forward(250)

graph.penup()

graph.goto(5,250)

graph.write('y',font=('Cambria',12,'italic'))

graph.goto(0,0)

graph.pendown()

graph.backward(250)

graph.forward(250)

def f(x):

'''f(x) -> float

generic function to be graphed'''

return x**2

def decrease_to_fit(zoom):

'''decrease_to_fit(zoom) -> tup

decreases x to fit the graph'''

minX = -250/zoom

maxX = 250/zoom

# fit for negative x

while abs(f(minX)) > 250/zoom:

minX += 0.5/zoom

# fit for positive x

while f(maxX) > 250/zoom:

maxX -= 0.5/zoom

# return tuple of min and max

return (minX,maxX)

def graph_function(t,zoom=10):

'''graph_function(t,zoom) -> none

draws the graph of a function using turtle t

and is zoomed in to zoom'''

t.pensize(2)

# go to the start without drawing a ling

x,maxX = decrease_to_fit(zoom)

t.penup()

t.goto(x*zoom,f(x)*zoom)

t.pendown()

# draw the graph

while x <= maxX:

x += 0.01

t.goto(x*zoom,f(x)*zoom)

graph_function(graph,100)

wn.mainloop()