Maximisation of a box cut on 4 sides

A piece of rectangular paper (20 × 30cm) is supplied to make a box of the largest possible volume, by cutting out the corners and folding up the sides. The cuts must be square (ie both sides are reduced by the same amount). How big should the cuts be to maximise the volume of the box?

Using the information above, we have the equation

 V = (20 – 2x)(30 – 2x)(x)

a) Use Matlab to find the volume of the box with a range of values of x from 0 to 10 in steps of 0.001. [You may need to use the element-wise multiplication, “.*”, in your formula]

[the cyclist]

Please read this: http://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers

Answer 1

[Sean de Wolski]

Something like:

V = @(x)-(20 - 2*x)*(30 - 2*x)*x
x = fminunc(V,0)