Question

What is the radius of the circle whose equation is x^2 + y^2 = 9?

9?

Answer 1

3

Answer 2

nope...here's a hint the equation of a circle is (x-h)^2 + (y-k)^2 = r^2

Answer 3

so 9 is just r^2

to find r you need to take the square root..make sense?

Answer 4

A cricle centered at the origin has the equation \[x^2 + y^2 = r^2\]if \(r^2\) is 9, what is r, the radius?