Question

this circle is centered at the origin and the length of its radius is 4 what is the circles equation

Answer 1

Given that the circle is centered at the origin.

$(h,k)=(0,0)$

And the radius of the circle is 4;

$r=4$

Recall that the general equation of a circle is;

$(x-h)^2+(y-k)^2=r^2$

Substituting the given values;

$\begin{gathered} (x-h)^2+(y-k)^2=r^2 \\ (x-0)^2+(y-0)^2=4^2 \\ x^2+y^2=16 \end{gathered}$

Therefore, the equation of the cir