What is the radius of the circle whose equation is x² + y² = 9?

Solution:

The general equation of the circle is given by

(x - h)² + (y - k)² = r²

Where, (h, k) is the center

r is the radius

Given,

The equation of the circle is x² + y² = 9

So, r² = 9

Taking square root,

r = 3

Therefore, the radius of the circle is 3 units.

What is the radius of the circle whose equation is x² + y² = 9?

Summary:

The radius of the circle whose equation is x² + y² = 9 is 3 units.