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Prove the following: ∫-11x17cos4xdx=0 - Mathematics

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Question

Prove the following:

`int_(-1)^1 x^17 cos^4 xdx = 0`

Sum
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Solution

Let `I = int_(-1)^1 x^17 cos^4 x " dx" = 0`

Let f(x) = x17 cos4 x

f(-x) = (-x)17 cos4 (-x)

= - x17 cos4 x   ....` [because int_(- a)^a f(x) = 0  "if"  f(- x) = - f]`

∴ I = 0

∴ f (x) is an odd function, hence I = 0.

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Chapter 7: Integrals - Exercise 7.12 [Page 353]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 7 Integrals
Exercise 7.12 | Q 36 | Page 353

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