# Calculus

posted by
**sh**
.

To construct a tincan, V=32pi m^3, The cost per square meter of the side is half of the top and bottom of can. What are the dimensions and the cost?

V=πr²h=32pi SA=2πr²+2πrh

h=32/r²

Domain={r>o}

Let x be the cost, I subbed 32/r² for h

C=f(r)=2πxr²+(32xπ/r)

f'(r)=4πxr + 32xπ/r²

common denominator

f'(r)=(4πxr³+ 32xπ)/r²

I factored, it, r=-2, which is not in the domain.

Where did it go wrong?