# Integration by part not working

1. Oct 27, 2016

### nysnacc

1. The problem statement, all variables and given/known data
I have three integrals, from 0 to 1
∫ -4x5 ex3-x4dt
∫ 3x4ex3-x4dt
∫ 2tex3-x4dt

2. Relevant equations
Looks like they are not integrable, as ex3-x4 is not,
I tried by part, let say u =
3. The attempt at a solution

2. Oct 27, 2016

### Staff: Mentor

If you have written the integrals exactly as they were given, they should all be very easy. The variable of integration in all three is t (based on the dt part).

As an example, $\int e^x dt = e^x \int 1 dt = e^x (t + C)$

3. Oct 27, 2016

### nysnacc

Oh, written wrong, should be dx,sorry

4. Oct 27, 2016

### Staff: Mentor

Should the last one you listed be $\int_0^1 2xe^{x^3 - x^4}dx$?

Can you post a photo of the problems? I'm wondering if there's something you left out.

5. Oct 27, 2016

### nysnacc

Yes, thanks I solved it tho, by recombine the parts in the integral and using by part