Question

Identify the center and radius of the following circle: (x + 9)^2 + (y - 5)^2 = 64

Answer 1

`\bf \textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{}{ h},\stackrel{}{ k})\qquad \qquad radius=\stackrel{}{ r}\\\\ -------------------------------\\\\ (x+9)^2+(y-5)^2=64\implies [x-(\stackrel{h}{-9})]^2-[y-\stackrel{k}{5}]^2=\stackrel{r}{8^2} \\\\\\ center~~(-9~,~5)\qquad radius=8`