# Homework Help: Have a question about integrals

1. Oct 21, 2007

### kevinf

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

integrate (tan4x)^2.

2. Relevant equations

3. The attempt at a solution

i have tried the box method but it won't work. i have also been told to do the integral b parts using dv, v, u, and du. i have heard of that method but the teacher insists on teaching the box method. is it possible with the box method.

2. Oct 21, 2007

### rocomath

$$\int\tan^{2}{4x}dx$$

yes? ima start working on it. idk what the box method is. also, show some work or i won't post anything if i even get anywhere, lol.

3. Oct 21, 2007

### kevinf

i have tried to convert that to the sin over cos and then integrating but i don't have any idea what to do after that

4. Oct 21, 2007

### rocomath

dope! trig identity ...

5. Oct 21, 2007

### kevinf

anybody else got it?? i really just want the steps getting to the answers not necessarily the answer

6. Oct 21, 2007

### rock.freak667

Hmmm....remember $$sec^2A=1+tan^2A$$ so if ever A=4x .....you can replace tan$$^2$$4x with sec

7. Oct 21, 2007

### rocomath

i told you!

$$\int\tan^{2}{4x}dx=\int(\sec^{2}4x-1)dx$$

8. Oct 21, 2007

### PowerIso

I'm simply wondering, what is the box method? I never heard of it.

9. Oct 21, 2007

### rocomath

maybe it's the table method?

10. Oct 22, 2007

### transgalactic

here is my answer in the file

i have added a file with my solution

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11. Oct 22, 2007

### rocomath

your picture will have to be approved