Thread: (minimum/maximum problem) Minimum price for gasline

Hi all!

I have the following math problem to be solved, and I really can't find it

"A gasline has to be put from the coast to the city, begin and endpoint are determined. The costs along the coast are 750 dollar / kilometer, and through the city 1250 dollar / kilometer. Give the function to determine the minimum price - also give the minimum price."

IMAGE:

Originally Posted by zerox

Hi all!

I have the following math problem to be solved, and I really can't find it

"A gasline has to be put from the coast to the city, begin and endpoint are determined. The costs along the coast are 750 dollar / kilometer, and through the city 1250 dollar / kilometer. Give the function to determine the minimum price - also give the minimum price."

I assume the distance "x" is along the coast.

let C(x) be cost as a function of x



find C'(x) and minimize

Great, thank you!

May I ask how you came to this solution? I have been staring at the picture for quite a while and failed to understand how to solve it.

Originally Posted by zerox

Great, thank you!

May I ask how you came to this solution? I have been staring at the picture for quite a while and failed to understand how to solve it.

I didn't solve the problem ... just set it up.

the expression for the length of the line through the city was determined using Pythagoras.