What is the vertex of a parabola in the form of the equation y=a(x - h)2 + k?
(a, k) (a, h) < --i got this just double checking (h, k) (h, -k)

The equation a(x−h)2+k means that the vertex of the parabola is at the point (h,k) . If a is positive, the graph opens up, and if a is negative, the graph opens down.
h is the negative of the x-coordinate in of the vertex, and k is the y-coordinate. If your vertex is (−1,1) , thenh=? k=?

Since the x-coordinate of your vertex is -1, h=−(−1)=1 , and since the y-coordinate is 1, k=1 . Now we still have to find what a is.

First, since the parabola is opening downwards, a is negative. But what's the value? Well, know the point (0,0) is on the graph, so we just plug that in to get 0=a(0+1)2+1=a+1 Solving for a , we get a=−1 .

Your form is y=a(x−h)2+k where a=−1 , h=−1 , and k=1 .

in the parentheses you have (x−(−1) . The negatives cancel each other out, and you would get (x+1)