Question

A point on the circle `x^2 + y^2 = 169` has an x- coordinate of 12, what are the possible y coordinates?

Answer 1

`y=+-5`.

Explanation:

`x^2+y^2=169, and, x=12`.

`:. 12^2+y^2=169`.

`:. y^2=169-144=25`.

`:. y=+-5`.