Question Detail
Question
Evaluate ∫ Cos(ln x) / x dx
Correct Answer
Option D is the correct answer.
Detailed Explanation
To evaluate the integral, use the substitution method. 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. Replacing u with ln x, the final answer is sin(ln x) + C.
Hint
Consider a substitution where u is the argument of the cosine function.