Question

求经过点m4,3且与圆x^2+y^2-4y+2=0相切于N(1,3)的圆的方程

Answer 1

M(4,3),N(1,3)

P:(x^2+y^2-4y+2=0

P(0,2)

PN:y=x+1

C(a,1+a)

(a-1)^2+(1+a-3)^2=(a-4)^2+(1+a-3)^2

a=2.5

r^2=2.5

C:(x-2.5)^2+(y-3.5)^2=2.5