Question

The point (3, 4) is on a circle with a center (1, 4).
Find the radius of the circle.
Write the standard equation of the circle.
Graph the circle.

Answer 1

Check the picture below.

$\textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{1}{ h},\stackrel{4}{ k})\qquad \qquad radius=\stackrel{2}{ r} \\\\[-0.35em] ~\dotfill\\\\ (x-1)^2~~ + ~~(y-4)^2~~ = ~~2^2\implies (x-1)^2~~ + ~~(y-4)^2~~ = ~~4$