Question Detail

MTH 102 MTH 102 Past Questions Objective Question

Question

Obtain ∫ sin²x dx
Options
A x - sin 2x
B x + sin 2x
C x - sin x cos x
D x/2 + sin 2x/4
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

To integrate sin²x, we use the power-reducing identity: sin²x = (1 - cos 2x) / 2.∫ sin²x dx = ∫ (1 - cos 2x) / 2 dx= (1/2) ∫ (1 - cos 2x) dx= (1/2) [ x - (sin 2x / 2) ] + C= x/2 - (sin 2x) / 4 + C.The mathematically correct answer is x/2 - (sin 2x)/4. The highlighted option D is x/2 + (sin 2x)/4, which has a sign error.

Hint

Use the power-reducing trigonometric identity for sin²x, which is sin²x = (1 - cos 2x) / 2.

Question Info