Question

Which of the following is the graph of (x-2)^2 + (y+1)^2 = 9? (Brainly doesn't seem to want to let me put up pictures. Sorry guys.)

Answer 1

If you want to cheat, paste the formula in Wolfram Alpha. However, this one is not that difficult. From the fact that x and y are squared you can infer that this is a circle. The 9 reveals that the radius r^2 is 9, so radius is 3.

The (x-2) tells us that the circle is shifted to the right by 2. Likewise, y+1 shifts it down by one. So the center is at (2,-1). If the equation would be x^2 + y^2 = 9, you'd have a circle exactly on the origin.

Hopefully this helps you break down the equation and pick the right picture!