Math Is Fun Forum

1a2b3c2212

Member

Registered: 2009-04-04

Posts: 419

how to find minimum value of T

T>0, 0<x<1200.

How do I find the minimum value of T ?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: how to find minimum value of T

Hi 1a2b3c2212;

I hope you began by plotting T first. This will give you a rough estimate where the extrema are.

To find the minimum we diff. T with respect to x.

First term is easy:

For the next term:

We use the chain rule.

Say:

And

Then:

That's the first part of the chain rule formula. Now we need dT / du.

We have everything we need, start plugging in.

To find the maxima or minima you look for where the derivative is equal to 0. So set dT / dx = 0 and solve and you will have your minima. You should already know where it is approximately.

Post if you get stuck in solving.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: how to find minimum value of T

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1a2b3c2212

Member

Registered: 2009-04-04

Posts: 419

Re: how to find minimum value of T

Thanks soroban!