Question Detail

MTH 102 MTH 102 Past Questions Objective Question

Question

Obtain ∫sin² x dx
Options
A <sup>1</sup>/<sub>2</sub>x - <sup>sin 2x</sup>/<sub>2</sub>
B <sup>1</sup>/<sub>4</sub>x + <sup>sin 2x</sup>/<sub>2</sub>
C <sup>1</sup>/<sub>4</sub>x - <sup>sin x</sup>/<sub>4</sub>
D <sup>1</sup>/<sub>2</sub>x - <sup>sin 2x</sup>/<sub>4</sub>
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

To integrate sin² x, we use the power-reduction trigonometric identity:sin² x = (1 - cos 2x)/2Now, substitute this into the integral:∫sin² x dx = ∫(1 - cos 2x)/2 dx= 1/2 ∫(1 - cos 2x) dxIntegrate term by term:= 1/2 (∫1 dx - ∫cos 2x dx)= 1/2 (x - sin 2x/2) + CDistribute the 1/2:= 1/2x - sin 2x/4 + C. This matches option D.

Hint

Use the trigonometric identity sin² x = (1 - cos 2x)/2 to simplify the integrand before integration.

Question Info