Question Detail
Question
Evaluate
∫ Cos(ln x) / x dx
∫ Cos(ln x) / x dx
Correct Answer
Option D is the correct answer.
Detailed Explanation
To evaluate the integral, use u-substitution. Let u = ln x. Then the differential du = (1/x) dx. Substituting these into the integral gives ∫ Cos(u) du. The integral of Cos(u) with respect to u is Sin(u) + C. Substituting back u = ln x, we get Sin(ln x) + C.
Hint
Consider using u-substitution. What would be a good choice for 'u' in this integral?