Question

What is the the vertex of `y=2x^2+15x -2`?

Answer 1

`x_("vertex")=-3.75`

I will let you work out `y_("vertex")`

Explanation:

Given:`" "y=2x^2+15x-2`

A quick way of finding `x_("vertex")` is as follows:

Write as `" "y=2(x^2+15/2x)-2`

Now apply :`" "(-1/2)xx15/2 = -15/4 = 3.75`

`color(blue)(x_"vertex"=-3.75)`
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Now substitute back into the original equation to find `y_("vertex")`