complete teh square isolate x terms y=(x^2+6x)-12 take 1/2 of 6 and squaer it then add positive and negative inside parenthasees 6/2=3, 3^2-9 y=(x^2+6x+9-9)-12 comlete the square y=((x+3)^2-9)-12 y=(x+3)^2-9-12 y=(x+3)^2-21
for y=(x-h)^2+k vertex is (h,k) axis of symmetry is x=h
given y=(x-(-3))^2+(-21) vertex is (-3,-21) axis of symmetry is x=-3
