Question

What is the standard form of the equation of a circle with its center at (2, -3) and passing through the point (-2, 0)?

(x − 2)2 + (y + 3)2 = 5

(x + 2)2 + (y − 3)2 = 25

(x − 2)2 + (y + 3)2 = 25

(x − 2)2 − (y + 3)2 = 5

Answer 1

For future reference, posting the same question right after can be considered spam. And again; There are two steps to this problem. First is to find the radius, and the second is to write out the standard form. You can find the radius by finding the distance between the center and the point the circle passes through. For that, you use the distance formula: \[\large d=\sqrt{(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}}\] Then put it in standard form: \[\large (x-h)^{2}~+~(y-k)^{2}=r^{2}\]
\[\large (h,k)~=~Center~coordinates~of~circle\]
\[\large r~=~radius\]