# How do you evaluate the integral int costheta/(1+sintheta)?

$\text{F"(x) = ln|sintheta +1|+"C}$
This is a standard integral $\int \frac{f ' \left(\theta\right)}{f \left(\theta\right)} = \ln | f \left(\theta\right) | + \text{C}$.
So $\text{F"(x) = ln|1+sintheta| + " C}$