Math Is Fun Forum

srstudogg@yahoo.com

Member

Registered: 2011-09-30

Posts: 2

Need a bit of help with this differential equation

beta = e^(lambda*x)(1+(lambda*x)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,583

Re: Need a bit of help with this differential equation

hi srstudogg

Firstly, it is not recommended to give out email addresses on this forum.  So maybe you should cancel this membership and re-join with a different name.

Now to the problem:

You say this is a differential equation?   But it has no differential component.

I'll assume you meant

You can do this by using 'integration by parts'

Let

Then

So the integral becomes

Which should be straight forward for you to finish off.

Post back if this wasn't what you wanted or you need more help with any line.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

srstudogg@yahoo.com

Member

Registered: 2011-09-30

Posts: 2

Re: Need a bit of help with this differential equation

Bob,

Sorry if that was not clear.  I just re-worked the problem and want to solve for lambda.  Can this be done?  I can't seem to figure it out.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Need a bit of help with this differential equation

Hi;

Bob is right in pointing out that is not a differential equation.

Solving an equation means determining the relationship between variables. Solving DE means finding a family of functions.

This is an equation, notice there are only variables in it.

If that is the equation you want it will not be possible to solve for lambda in terms of elementary functions. The answer will involve the Lambert function.

This a DE. Notice it contains a derivative.

Which do you mean?

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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.