Originally Posted by

**raymac62** Let me explain what I know (or at least think I know) so that there is a better understanding of context:

C = the total cost for producing the cedar chest.

V = 1440 - In someway I have to take this value and substitute it into the equation so I can determine the value of at least 1 variable.

Then, I have to find the derivative, and solve for x when it is equal to zero.

I am not sure how I can go about expressing the total cost with only a single variable.

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Obviously, what you posted was not a pristine solution. Nonetheless, why have you expressed the volume as 2x^2h? That makes absolutely no sense to me. I do not see how that is algebraically equivalent to expressing V as 2x^2 * h. However, it must mean something to you. If you would care to explain...

Thanks in advance.

Sincerely,

Raymond