# Homework Help: Integration using inverse trig indentities?

1. Feb 17, 2015

### Cpt Qwark

1. The problem statement, all variables and given/known data
1.$$\int{\frac{sinx}{1+cos^{2}x}} \, dx$$
2.$$\int{\frac{1}{13-4x+x^2}} \, dx$$

2. Relevant equations
Inverse trig identities.

3. The attempt at a solution
For the first one, I'm not too sure about what to do with the $$sinx$$ on the numerator and i have tried u-substitution to no avail (different answer). For the second one, I tried factorising but only had solutions for $$x\inℂ$$.

2. Feb 18, 2015

### eple

You can maybe try to start with the substitution u = cos(x) and reforming the integral. A second substitution will be necessary after the first substitution.

3. Feb 18, 2015

### Raghav Gupta

Second substitution is not necessary. It can be done in that first one.

4. Feb 18, 2015

### HallsofIvy

For the second integral start by completing the square in the denominator.