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NCERT Class XII Mathematics Chapter - - Solutions

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Choose the correct answer in Exercises 227 and 228.
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Question : 228 of 271
Marks: +1, -0
The value of ∫0π/2log⁡(4+3sin⁡x4+3cos⁡x)dx\int\limits_{0}^{\pi/2}\log\left(\frac{4+3\sin x}{4+3\cos x}\right)dx is
Solution:  
Let I=∫0π/2log⁡(4+3sin⁡x4+3cos⁡x)dxI=\int\limits_{0}^{\pi/2}\log\left(\frac{4+3\sin x}{4+3\cos x}\right)dx
Also, I=∫0π/2log⁡[4+3sin⁡(π/2−x)4+3cos⁡(π/2−x)]dxI=\int\limits_{0}^{\pi/2}\log\left[\frac{4+3\sin(\pi/2 - x)}{4+3\cos(\pi/2 - x)}\right]dx
⇒I=∫0π/2log⁡(4+3cos⁡x4+3sin⁡x)dx\Rightarrow I=\int\limits_{0}^{\pi/2}\log\left(\frac{4+3\cos x}{4+3\sin x}\right)dx
⇒I=−∫0π/2log⁡(4+3sin⁡x4+3cos⁡x)dx\Rightarrow I=-\int\limits_{0}^{\pi/2}\log\left(\frac{4+3\sin x}{4+3\cos x}\right)dx
⇒I=−I\Rightarrow I=-I
⇒2I=0⇒I=0\Rightarrow 2I=0\Rightarrow I=0
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