Question

A circle is centered at (3, 8) and is tangent to the x-axis. Write its equation in standard form

Answer 1

the general equation of a circle is \[(x-h)^2+(y-k)^2=r^2\]where it's center is \[(h,k)\]use that formula

Answer 2

you can use the fact that the circle is tangent to the x-axis to find r if you are clever ;)