Question

Which is an equation of a circle with center (-5, -7) that passes through the point (0, 0)?

Answer 1

what's the radius of it anyway? \(\bf \textit{distance between 2 points}\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
&({\color{red}{ -5}}\quad ,&{\color{blue}{ -7}})\quad &({\color{red}{ 0}}\quad ,&{\color{blue}{ 0}})
\end{array}\qquad
d = \sqrt{({\color{red}{ x_2}}-{\color{red}{ x_1}})^2 + ({\color{blue}{ y_2}}-{\color{blue}{ y_1}})^2}
\\ \quad \\\\ \quad \\
(x-{\color{brown}{ h}})^2+(y-{\color{blue}{ k}})^2=r^2\qquad center\ ({\color{brown}{ h}},{\color{blue}{ k}})\quad radius=r\)