find the radius for x ^2 + y ^2 = 5

Question

I need help finding the radius of the circle.

Answer 1

x² + y² = 5

 

What is the equation for a circle?

 

(x-h)² + (y-k)² = r²

 

Where (h,k) is the location of the center of the circle and r is the radius.  The center of your circle is located at (h,k) = (0,0).  So what is r² in your equation?

Answer 2

 

(x-h)²+(y-k)²=r² where (h,k) is the center and r is the radius

x²+y²=5 becomes x²+y²=(√5)²

the center is the origin (0,0) and the radius is √5