Question

What is the vertex of `y= 2x^2 - 18x -6`?

Answer 1

`x_("vertex")=+9/2`
I will let you work out `y_("vertex")` by substitution

Explanation:

Write as:`" "y=2(x^2-18/2 x) -6`

Apply `" "(-1/2)xx(-18/2) = + 9/2`

`x_("vertex")=+9/2`
'~~~~~~~~~~~~~~~~~~~~~~~~~~~
To derive `y_("vertex")` substitute `x=9/2` into the original equation and solve for y