Question

If the point (1,5) lies on a circle whose center is at the origin, what is the equation of the circle?

Answer 1

x^2 + y^2 = 26.

Explanation:

The center is at (0, 0) and the radius is sqrt (1^2 + 5^2) = sqrt 26

The general form is

x^2 + y^2 = r^2 so here it is:

x^2 + y^2 = 26.