Question 766280
Given is {{{f(x)=-x^2-16x+8}}}.


factor a -1:
{{{-1(x^2+16x-8)}}}


Determine the missing square term:
{{{(16/2)^2=64}}}


Add and subtract 64 inside the grouped polynomial factor:
{{{(-1)(x^2+16x+64-64-8)}}}


Factor the desired square term existing inside the parentheses:
{{{(-1)((x+8)^2-72)}}}.... and take care of a little bit more of the arithmetic..


Remultiply:
{{{-(x+8)^2+72}}}


Function ready to graph is {{{f(x)=-(x+8)^2+72}}}


{{{graph(450,450,-15,15,-5,80,-(x+8)^2+72)}}}