Question

A circle has it center at (-2, -3) and a radius of 3 units. What is the equation of the circle?

Answer 1

The equation for a circle in standard form is
`(x-h)^2+(y-k)^2=r^2`, where h and k are the coordinates of the center. Our center has an h value of -2 and a k value of -3 with an r value of 3. Fitting those values into our standard form of a circle we have
`(x-(-2))^2+(y-(-3))^2=3^2`. Subtracting a negative is the same as adding, and squaring the right side gives us 9, so the equation is
`(x+2)^2+(y+3)^2=9`. Third choice from the top.