Question Detail

MTH 102 MTH 102 Past Questions Objective Question

Question

Find dy/dx, if y = loge(cos x).
Options
A <i>cot x</i>
B <i>-cot x</i>
C <i>-tan x</i>
Correct Answer
D <i>tan x</i>
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).To differentiate, use the chain rule: d/dx(ln(f(x))) = f'(x)/f(x).Here, f(x) = cos x, so f'(x) = d/dx(cos x) = -sin x.Therefore, dy/dx = (-sin x) / (cos x) = -tan x.

Hint

Remember that loge is the natural logarithm, ln, and apply the chain rule.

Question Info