Question

Find the vertex of the graph f(x)=-x^2+6x+1

Answer 1

Giving the function

$f(x)=x^2+6x+1$

the vertex is giving by

$h=\frac{-b}{2a}$

where

a=1

b=6

c=1

then

$h=\frac{-6}{2*1}$$h=\frac{-6}{2}=-3$

then

$f(-3)=-3^2+6(-3)+1$$f(-3)=9-18+1$$f(-3)=-8$

then the vertex is in the point

(-3,-8)