Rewrite the function in “vertex from (by completing the square) 1) f(x) =-x^2 +8x+3

X^2 + 8x + 3
= (x + 4)^2 - 16 + 3
= (x + 4)^2 - 13 Answer.

You divide the + 8 by 2 to get the +4  and you then subtract 4^2 ( which is the -16).