A closed rectangular box with a square box with a square base and with a capacity of 1.5 meter cubed is to be made The material for the top and bottom costs $3.00 per meter squared and for the sides is $4.00 per meter squared. Find the minimum cost.
I was able to get the 2 equations which are:
(x^2)(height) = 1.5
3x + 4h is a minimum
dx/dh = 3x + 6/x^2
then I equate this to zero
which gave me x = 4 and height = 0.09375
The cost of which is $12.375
But this is not a correct solution.
It is a multiple choice question, the selections are:
a. $36.68 b. $45.86 c. $28.68 d. $43.98
Any idea where I get wrong ?