Your equation 
is in the form 
The vertex only relies on "a" and "b" though, so that +9 doesn't really matter in this case. The vertex of a parabola is located where
So your x-coordinate is -1. You need to find f(-1) to find your y-coordinate, and then you list it in the form (-1, y).
The vertex only relies on "a" and "b" though, so that +9 doesn't really matter in this case. The vertex of a parabola is located where
So your x-coordinate is -1. You need to find f(-1) to find your y-coordinate, and then you list it in the form (-1, y).