# Homework Help: Integration by Parts

1. Jan 6, 2008

### bondgirl007

1. The problem statement, all variables and given/known data

Integrate x^2 e^x^3 dx

2. Relevant equations

I = uv - integral of u'v

3. The attempt at a solution

I don't know where to begin this question at all and have been stuck on it for the past half hour. Any help would be really appreciated. :(

2. Jan 6, 2008

### Dick

e^x^3 can mean either e^(x^3) or (e^x)^3. Use parentheses! (If not TeX). If it's the former then d(x^3)=3*x^2, suggest a u substitution.

Last edited: Jan 6, 2008
3. Jan 6, 2008

### bondgirl007

Sorry about that. I'll try again.

4. Jan 6, 2008

### bondgirl007

I'm not sure how to use the tags here so I'll just post a picture.
http://img231.imageshack.us/img231/1954/52551832cl9.png [Broken]

Last edited by a moderator: May 3, 2017
5. Jan 6, 2008

### olgranpappy

that doesn't really help...

6. Jan 6, 2008

### bondgirl007

That's how it is in my textbook though.

7. Jan 6, 2008

### Dick

Ok, we'll guess. I think it probably means e^(x^3). Can you suggest a u substitution?

8. Jan 6, 2008

### olgranpappy

...in which case, you don't need to "integrate by parts". you just need the substitution which was suggested.

(which bond girl are you? Ursella Andress?)

9. Jan 6, 2008

### bondgirl007

Here's what I have done
u = x^2
v = 3x^2 e^(x^3)
du = 2x dx
dv = e^(x^3)2x dx

I = x^2 3x^2 e^(x^3) - integral of 3x^2 e^(x^3)

I'm not sure how to integrate the 3x^2 e^(x^3).

10. Jan 6, 2008

### olgranpappy

use the substitution y=x^3 and that's it. just "change variables" not "integrate by parts".

11. Jan 6, 2008

### bondgirl007

I'll try that - thanks!!