Definite Integration Question 457

Question: $ \int_0^{\pi /2}{|\sin x-\cos x|dx=} $

[Roorkee 1990; MP PET 2001; UPSEAT 2001]

Options:

A) 0

B) $ 2(\sqrt{2}-1) $

C) $ \sqrt{2}-1 $

D) $ 2(\sqrt{2}+1) $

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Answer:

Correct Answer: B

Solution:

$ \int_0^{\pi /2}{|\sin x-\cos x|dx} $

$ =\int_0^{\pi /4}{-(\sin x-\cos x})dx+\int _{\pi /4}^{\pi /2}{(\sin x-\cos x)dx}=2(\sqrt{2}-1) $ .