Question

Write the equation in standard form for the circle with center (3,9) and radius 8

Answer 1

Solution:

To find the equation of a circle in standard form, the formula is

$\begin{gathered} (x-h)^2+(y-k)^2=r^2 \\ Where \\ (h,k)\text{ is the center and r is the radius} \end{gathered}$

Given that;

$\begin{gathered} (h,k)=(3,9) \\ r=8 \end{gathered}$

Substitute the values of h, k and r into the formula above

$(x-3)^2+(y-9)^2=8^2$

Hence, the equation of the circle in standard form is

$(x-3)^{2}+(y-9)^{2}=8^{2}$