解連立方程式(三)

#解方程式x,y 並畫出 L1=x-y,L2=-x-y+2
import matplotlib.pyplot as plt
from sympy import Symbol,solve
impo=rt numpy as np
x=Symbol("x")
y=Symbol("y")
eq1=x-y
eq2=-x-y+2
ans=solve((eq1,eq2))
print(ans)
x1=np.linspace(-20,20,100)
y1=x1
x2=np.linspace(-20,20,100)
y2=-x2+2
plt.plot(x1,y1)
plt.plot(x2,y2)
plt.plot(ans[x],ans[y],"-o")
plt.text(ans[x]-2,ans[y]+4,"("+str(ans[x])+","+str(ans[y])+")")
plt.grid()
plt.axis("equal")
plt.show()