Question Detail

MTH 102 MTH 102 Past Questions Objective Question

Question

Obtain ∫sec x dx
Options
A secx tan x
B ln|sec x tan x|
C ln|sec x + tan x|
Correct Answer
D sec² x tan x
Correct Answer

Option C is the correct answer.

Detailed Explanation

The integral of sec x is a standard result in calculus.∫sec x dx = ln|sec x + tan x| + CTo verify this, one can differentiate ln|sec x + tan x|:d/dx [ln|sec x + tan x|] = (1 / (sec x + tan x)) * d/dx (sec x + tan x)= (1 / (sec x + tan x)) * (sec x tan x + sec² x)= (1 / (sec x + tan x)) * (sec x (tan x + sec x))= sec xThus, the integral of sec x is ln|sec x + tan x| + C.

Hint

This is a fundamental integral that should be memorized or derived. Recall how multiplying by (sec x + tan x) / (sec x + tan x) can simplify the integral for substitution, leading to a logarithmic form.

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