What is the equation of a circle whose center is at the origin and whose radius is 16?

Solution:

Given center of circle is origin and radius is 16 units

We know that equation of a circle with radius r and centre (h,k) is

(x - h)² + (y - k)² = r²

Here, centre is origin hence, h = 0 and k = 0, r = 16

⇒ (x - 0)² + (y - 0)² = 16²

⇒ x² + y² = 256

The equation of the circle is x² + y² = 256.

What is the equation of a circle whose center is at the origin and whose radius is 16?

Summary:

The equation of a circle whose center is at the origin and whose radius is 16 is x² + y² = 256.