Question

The equation for the circle below is x² + y2 = 16. What is the length of the
circle's radius?

Answer 1

4

Explanation:

Answer 2

radius = 4

Explanation:

Recall that the equation of a circle centered at (0,0) on the plane is given by the formula:

`x^2+y^2=r^2`

where "r" is the radius of the circle.

S, in our case, since the equation reads:

`x^2+y^2=16`

16 corresponds to the square of the circle's radius. Therefore the radius can be found via:

`r^2=16\\r=+/-√(16\\)\\r=+/-4`

and since we are talking about the length of a radius, we choose the positive option for the answer: radius = 4