Question

circle x squared plus y squared equal to 16

Answer 1

Answer:

This is going to be the graph of a circle with the center at the origin and a radius of 4. 

Explanation:

The formula for a circle is:

(x−xc)2+(y−yc)2=r2

The center of this circle will be located at the point (x_c, y_c).

You can expand your equation above to look like this:

(x−0)2+(y−0)2=16

From this equation, you know that the center of the circle will be located at (0;0).

Your radius can be found by using the equation as well. In your equation, 
r2=16
∴√r2=√16⇒r=4.

Answer 2

Radius is 4. Because general equation of circle having centre at origin is x²+y²=r²
The given eqn is x²+y²=4²
Hence, r=4