# formula for e^x-ye^x integral

• May 3rd 2013, 07:00 AM
mathlover10
formula for e^x-ye^x integral
$\int (ae^{x}-ye^{x})=-ye^{x}+(a+1)e^{x}+c$ this is an interesting technique where you just add (a+1)e^x to find the antiderivative
• May 3rd 2013, 07:27 AM
hollywood
Re: formula for e^x-ye^x integral
Do you have a question?

- Hollywood
• May 3rd 2013, 07:42 AM
mathlover10
Re: formula for e^x-ye^x integral
sure how do you solve integrals in the complex plane?
• May 3rd 2013, 08:23 AM
HallsofIvy
Re: formula for e^x-ye^x integral
Quote:

Originally Posted by mathlover10
$\int (ae^{x}-ye^{x})=-ye^{x}+(a+1)e^{x}+c$ this is an interesting technique where you just add (a+1)e^x to find the antiderivative

There is no "dx" or "dy". What are you integrating with respect to?
• May 3rd 2013, 04:42 PM
mathlover10
Re: formula for e^x-ye^x integral
how do you do integrals on the complex plane?
• May 3rd 2013, 06:53 PM
hollywood
Re: formula for e^x-ye^x integral
If you have a complex-valued function of a real variable, you can integrate the real and imaginary parts separately. If you have a function of a complex variable, then you'll need to do a path integral.

In this forum, people post the math problems they're having trouble with (and where they're having trouble), and we give them advice on how to get through the difficult parts.

- Hollywood
• May 4th 2013, 04:45 AM
mathlover10
Re: formula for e^x-ye^x integral
thanks! I'm still a math student....I guess this equation has the narrow condition that d/dx[g(x)]=g(x).... anyway in the Braun Differential Equations text he uses the product rule to prove a solution for the nonhomogeneous first order DE. I kind of like the text since he starts with analytical methods. I don't know if this is from Dr. Feynman, but kind of interesting to contemplate
• May 4th 2013, 07:53 AM
topsquark
Re: formula for e^x-ye^x integral
Quote:

Originally Posted by mathlover10
how do you do integrals on the complex plane?

New questions that are off topic belong in a new thread. As the original post didn't actually have a question....

-Dan
• May 4th 2013, 12:15 PM
HallsofIvy
Re: formula for e^x-ye^x integral
Quote:

Originally Posted by mathlover10
thanks! I'm still a math student....I guess this equation has the narrow condition that d/dx[g(x)]=g(x).... anyway in the Braun Differential Equations text he uses the product rule to prove a solution for the nonhomogeneous first order DE. I kind of like the text since he starts with analytical methods. I don't know if this is from Dr. Feynman, but kind of interesting to contemplate

And you still have no idea that what you wrote in your original post was non-sense?
• May 4th 2013, 01:47 PM
topsquark
Re: formula for e^x-ye^x integral
Good point. I hadn't really looked at the post beyond noting it had no question.

-Dan
• May 4th 2013, 06:35 PM
mathlover10
Re: formula for e^x-ye^x integral
it was just notation... $\int (ae^y-ye^y)dy=-ye^y+(a+1)e^y+c$
• May 4th 2013, 06:53 PM
Prove It
Re: formula for e^x-ye^x integral
I don't think the OP understands that in order for us to help, we need to know what they need help with. Some WORDS would be nice... ><
• May 4th 2013, 06:59 PM
Plato
Re: formula for e^x-ye^x integral
Quote:

Originally Posted by mathlover10
it was just notation... $\color{red}\int (ae^y-ye^y)dy=-ye^y+(a+1)e^y$

All of that is wrong!

You have no idea what any of this is about do you?

If that is the case, why are you doing this?

If that is not the case, then why are you so confused?
• May 4th 2013, 07:15 PM
mathlover10
Re: formula for e^x-ye^x integral
thanks! anyway it's an interesting challenge to try to do integrals after a drink and no sleep. by the way I have another thread on Wrinkled Spheres that you could look at and comment! so you think that Schey is a good book? I am just curious about the thought processes of professional mathematicians or physicists as in equation modeling, do they imagine an expression that they are looking for and which techniques do they use to arrive at the correct equation which in the case of physics I guess correlates with experimental results?
• May 5th 2013, 02:50 AM
mathlover10
Re: formula for e^x-ye^x integral
solution of higher degree polynomial equations?