How to solve the calculus pipeline optimization problem.

Question: Calculus Homework
An oil refinery is located on the north bank of a straight river that is 2 km wide. A pipeline is to be constructed from the refinery to storage tanks located on the south bank of the river 8 km east of the refinery. The cost of laying pipe is $200,000/km over land to a point P on the north bank and $400,000/km under the river to the tanks. To minimize the cost of the pipeline, how far from the refinery should P be located? (Round your answer to two decimal places in km.) 

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Answered By:

Doug C.
Math Tutor with Reputation to make difficult concepts understandable

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Written Explanation:

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