Question

What is the line of symmetry of the parabola y=x2+6x-9?

Answer 1

first we have to find the vertex (h,k) h is also x and it also is the a xis symmetry

1st: group the number
(X2+6x)-9

2nd: use b/2

6/2 = 3 , 3^2= 9

(X2+6x+9)-9-9

(X2 + 3)-18

Vertex is 3,-18 so the symmetry is 3