Question

What is the center of the circle with the equation x2 + y2 – 10x – 11 = 0 ?

Answer 1

Rearrange to standard form:-

x^2 - 10x + y^2 = 11
(x - 5)^2 - 25 + y^2 = 11
(x - 5)^2 + y^2 = 36

Center of circle = (5, 0)  and radius  = sqrt36  =  6