ExamBro
ExamBro
WBJEE · Maths · Definite Integration

The value of the integral \(\int_{0}^{\pi / 4} \frac{\sin x+\cos x}{3+\sin 2 x} d x\)
is equal to

  1. A \(\log _{e} 2\)
  2. B \(\log _{e} 3\)
  3. C \(\frac{1}{4} \log _{e} 2\)
  4. D \(\frac{1}{4} \log _{e} 3\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\frac{1}{4} \log _{e} 3\)

Step-by-step Solution

Detailed explanation

Let \(I=\int_{0}^{\pi / 4} \frac{\sin x+\cos x}{3+\sin 2 x} d x\) \(=\int_{0}^{\pi / 4} \frac{\sin x+\cos x}{3+2 \sin x \cos x} d x\) \(=\int_{0}^{\pi / 4}-\frac{\sin x+\cos x}{(\sin x-\cos x)^{2}-4} d x\) Put \(\sin x-\cos x=t\) \(\Rightarrow \quad(\cos x+\sin x) d x=d t\) when…