- #1
Melawrghk
- 145
- 0
Homework Statement
[tex]\int \frac{26 dx}{{(169x^2+1)}^2}[/tex] <= the whole denominator is supposed to be squared...
The Attempt at a Solution
So I converted the thing in the denominator so that it has a square root:
[tex]\int \frac{26 dx}{{\sqrt{169x^2+1}}^4}[/tex]
Looking at the denominator, I realized I should do an inverse substitution:
13x=tan(t)
dx=sec2(t)*dt/13
I subbed that into the equation before and got:
[tex]\int \frac{26 * sec^2(t) * dt}{13*sec^4(t)}[/tex]
Simplifying which, I get:
2[tex]\int cos^2(t) dt[/tex]
Then I tried doing integration by parts, but I got nowhere - I kept getting cos^2 again... Please help me, this question frustrates me. Thanks in advance!
(Sidenote: I finally got my formulas all pretty, yay!)