Problem 21

Question

Find the indefinite integral. $$ \int \frac{\cos t}{1+\sin t} d t $$

Step-by-Step Solution

Verified
Answer
The indefinite integral of \( \frac{\cos t}{1+\sin t} \) with respect to \( t \) is \( \ln |1 + \sin t| \)
1Step 1: Substitute variable to simplify fraction
Let's use a substitution, let \( u = 1 + \sin t \). Then, differentiate \( u \) with respect to \( t \) to find \( du \) in terms of \( dt \). We find that \( du = \cos t \, dt \).
2Step 2: Substitute into Integral and Solve
Substituting \( u \) and \( du \) into the original integral gives us \( \int \frac{1}{u} \, du \), which simplifies to \( \ln |u| \).
3Step 3: Back Substitution
To finish the problem, substitute \( u \) back in terms of \( t \). This gives us our final answer, \( \ln |1 + \sin t| \).