Problem 23

Question

Find the indefinite integral. $$ \int \frac{\sec x \tan x}{\sec x-1} d x $$

Step-by-Step Solution

Verified
Answer
The indefinite integral of the given function is \( ln |sec x - 1| + C \)
1Step 1: Determine Suitable Substitution
Let's do a substitution: let \(u = sec x -1\). Then differential of \(u\) is given by \(du = sec x \cdot tan x dx \). This substitution simplifies the integrand to \( \int \frac{du}{u} \)
2Step 2: Solve the Integral
The integral now reduces to the form that we know easily: \( \int \frac{du}{u} = ln |u| + C \)
3Step 3: Substitute back original variable
Substitute back the original variable in place of \(u\) to get the final answer as \(ln |sec x - 1| + C \)