Question

The center of a circle is located at C(-7,-4). The y-axis is tangent to the circle at (0,-4). Find the equation of the circle.

Answer 1

\[x ^{2}+y ^{2}=49\]
\[(x-7) ^{2}+(y-4)^{2}+49\]
\[x ^{2}+(y+4)^{2}=16\]
\[(x+7)^{2}+(y+4)^{2}=49\]