Question

⒈ 过点C(-1,1)和D(1,3),圆心在x轴上.求圆的方程

Answer 1

1 (X-A)^2+Y^2=r^2

(-1,1),(1,3)

(-1-a)^2+1=r^2=(1-a)^2+y^2

a=2 r^2=10

(x-2)^2+y^2=10

2 O(0,y) |y-6|=5 y=1 or y=11

x^2+(y-1)^2=25 or x^2+(y-11)^2=25