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MTH 102 MTH 102 Past Questions Objective Question

Question

Find the integral: ∫ (cos x / sin² x - 2e2x) dx
Options
A cosecx - e<sup>2x</sup> + c
B - cosecx - 3e<sup>2x</sup> + c
C - cosecx - e<sup>2x</sup> + c
Correct Answer
D cosecx - 2e<sup>2x</sup> + c
Correct Answer

Option C is the correct answer.

Detailed Explanation

We can split the integral into two parts:∫ (cos x / sin² x) dx - ∫ (2e^(2x)) dxFor the first part, cos x / sin² x can be rewritten as (cos x / sin x) * (1 / sin x) = cot x * csc x. The integral of csc x cot x is -csc x. So, ∫ (cos x / sin² x) dx = -csc x + C1.For the second part, ∫ (2e^(2x)) dx, let u = 2x, then du = 2 dx. The integral becomes ∫ e^u du = e^u + C2 = e^(2x) + C2.Combining both parts: -csc x - e^(2x) + C.

Hint

Recall that (cos x / sin x) * (1 / sin x) = cot x * csc x. Also, remember the integral of e^(ax).

Question Info