Write the equation of the circle centered at ( 2 , 2 ) with radius 15.

Question

Write the equation of the circle centered at  with radius 15.

Answer 1

Square root of 15 = (x-2)² + (y-2)²

The idea is that any point on the circle can be represented by the Pythagorean theorem as a distance from the center. The this is you will always know the hypotinus to be the square of 15 and then it is a matter of inputting either a x or y value

Answer 2

Hi Juan G.,

The general equation for a circle is (x - h)² + (y - k)² = r², with (h, k) the center of the circle.

With the center at (h=2, k=2) and r = 15 we can insert them into this general equation:

(x - 2)² + (y - 2)² = 15²

(x - 2)² + (y - 2)² = 225, this is the equation for the circle with the parameters given.

I hope this helps, Joe.