F5 Maths circle

Centre of C1: (4,3). We can set C2

x^2 + y^2 + Dx + Ey + F = 0

Sub. P (-4, 3) and Q(4, -5) and M(4, 3)

25 - 4D + 3E + F = 0...(1)

41 + 4D - 5E + F = 0...(2)

25 + 4D + 3E + F = 0...(3)

(1) (3)=> D = 0 Then

25 + 3E + F = 0...(1)

41 - 5E + F = 0...(2)

=> E = 2, F = -31

So, C2: x^2 + y^2 + 2y - 31 = 0


2011-01-27 17:26:02 補充：
(3) - (1) 8D = 0

D = 0