Question

What is the equation of a circle with center at (4, -2) and a radius of 7?

Answer 1

let h= 4, k=-2 and r= 7 then

(x-h)^2 + (y-k)^2 = r^2

(x-4)^2 + (y+2)^2 = 7^2

x^2 -8x +16 + y^2 +4y +4 = 49

x^2 +y^2 -8x +4y +16 +4-49 = 0

x^2 + y^2 -8x +4y -29 = 0 is the required eq