Finding Extreme Volumes of V(x): A Box Model

[Jan Hill]

Homework Statement

The function V(x) = x(14-2x)(15-x) 0<x<7 models the volume of a box
Find the extreme values of V

and tell whether these represent the smallest and largest volumes or only the smallest or only the largest volumes

Homework Equations

The Attempt at a Solution

I found the derivative of the function to be 210 - 88x + 6x^2 and if I set this equal to 0,
I get 0 = 210 -88x + 6x^2
210 = 88x -6x^2

but where do I go from here?

 

[hotvette]

solve for x using quadratic formula.