Question Detail

MTH 102 MTH 102 Past Questions Objective Question

Question

Find dy/dx, if y = loge(cos x)
Options
A cotx
B -cotx
C -tanx
Correct Answer
D tanx
Correct Answer

Option C is the correct answer.

Detailed Explanation

The function is y = loge(cos x), which is equivalent to y = ln(cos x). Using the chain rule, the derivative of ln(u) is (1/u) * du/dx. Here, u = cos x, so du/dx = -sin x. Therefore, dy/dx = (1/cos x) * (-sin x) = -sin x / cos x = -tan x.

Hint

Recall the derivative of ln(u) and apply the chain rule, where u is cos x.

Question Info