Four identical squares are cut from the corners of a rectangular shet of metal with dimensions:

16 meters by 10 meters.

Find the dimensions of the box that has the maximum volume.

V=M^3

Length = 10m

Width = 16m

Height = x

Therefore the Function is:

v=x(16-2x)(10-2x)

v= x(160-12x-4x^2)

v=(160x-12x^2-4x^3)

Find the derivative and solve for v'=0.

v'=160-24x-12x^2

I'm stuck on solving v'=0.

The quadratics discriminant in my calculations is a negative, so using the quadratic formula does not work.

I don't know what the next step is.