In which form is the following function written?

y+20=8(x+7)^2

  (a variation of) vertex form

Step-by-step explanation:

For vertical scale factor "a" and vertex (h, k), the vertex form of the equation for a parabola can be written as ...

  y = a(x -h)^2 +k

If k is subtracted from this equation, an alternate form is ...

  y -k = a(x -h)^2

This latter version of vertex form is the form your equation has, where ...

start with a line segment pq that we will copy. mark a point r that will be one endpoint of the new line segment. set the compasses' point on the point p of the line segment to be copied. adjust the compasses' width to the point q. the compasses' width is now equal to the length of the line segment pq.

step-by-step explanation: