Answer and explanation

Correct answer: D.

  1. Step 1: Let , so .
  2. Step 2: .
Answer
.
Why not the others: : forgets the chain-rule factor . : puts a minus sign on the derivative of sine. : keeps the sine instead of changing it to cosine.

Practise more Differentiation.

Free questions with an explanation for every one, and full timed ESAT (Engineering and Science Admissions Test) mock tests.