Question

Find the equation (in standard form) whose center is (5, -3) and goes through (2, 5).

Answer 1

We can write this as

(x - 5)^2 + (y + 3)^2 = r^2

where r = radius

Plugging in the point (2,5) we have

(2-5)^2 + (5+3)^2 = r^2
r^2 =  9 + 64 = 73
so the required equation is

(x - 5)^2 + (y + 3)^2 = 73