#範例2-4：使用sympy繪圖sin(x)
from sympy import *
#設定變數x
x = symbols('x')
plot(sin(x))

#指定x範圍畫圖
plot(sin(x),(x,-5, 5))

#畫三條圖：y=x, y=sin(x), y=cos(x)
plot(x,sin(x),cos(x),(x,-5, 5))

#設定畫圖顏色
p1 = plot(x,sin(x),cos(x),(x,-5, 5),show=False)
p1[0].line_color = 'green'
p1[1].line_color = 'r'
p1.show()