Hi

ive had a problem to do of a trapezium tank

using the area of a trapezium rule where a=w b=w-2x and h=(sqrt of 4xw-w^2)/2

by substituting all the values in and simplifying the expression I finally end up with

(w-x*(sqrt(4xw-w^w))/2

Now i need to find the maximum volume the tank can hold which i know is to differentiate. Ive made a number of attempts but they are all dead ends. Please help