मराठी

On which of the following intervals is the function f given byf(x) = x100 + sin x –1 strictly decreasing?

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प्रश्न

On which of the following intervals is the function f given byf(x) = x100 + sin x –1 strictly decreasing?

पर्याय

  • (0,1)

  • `(pi/2, pi)`

  • `(0, pi/2)`

  • None of these

MCQ
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उत्तर

None of these

Explanation:

Given f(x) = x100 + sin x - 1,

f'(x) = 100 x99 + cos x

(a) Interval 0 < x < 1, 0 < 100 x99 < 100

And cos x = + positive

`therefore` f'(x) = + positive

Hence, the function f is increasing.

(b) Interval is `pi/2 < "x" < pi`

`therefore` f'(x) = 100 x99 + cos x = + positive

Hence, the function f is increasing.

(c) Interval is, `0 < "x" < pi/2`

Here, 100 x99 and cos x are both positive.

`therefore` f'(x) = + ve

Hence, the function f is increasing.

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पाठ 6: Application of Derivatives - Exercise 6.2 [पृष्ठ २०६]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 6 Application of Derivatives
Exercise 6.2 | Q 13 | पृष्ठ २०६

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