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Find the absolute maximum value and the absolute minimum value of the following function in the given interval: f (x) = sin x + cos x , x ∈ [0, π]

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प्रश्न

Find the absolute maximum value and the absolute minimum value of the following function in the given interval:

f (x) = sin x + cos x , x ∈ [0, π]

योग
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उत्तर

Given function f(x) = sin x + cos x, on the interval [0, `pi`]

f'(x) = cos x - sin x

If f'(x) = 0

Then cos x - sin x = 0

`therefore tan x = 1 => x = pi/4`

At x = 0, f(0) = sin 0° + cos 0° = 1

At `x = pi/4, f(pi/4) = sin  pi/4 + cos  pi/4`

`= 1/sqrt2 + 1/sqrt2`

`= 2/sqrt2`

`= sqrt2` 

At x = π, f (π) = sin π + cos π

= 0 - 1

= - 1

`therefore` absolute highest value = `sqrt2`

and absolute minimum value = -1

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अध्याय 6: Application of Derivatives - Exercise 6.5 [पृष्ठ २३२]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 6 Application of Derivatives
Exercise 6.5 | Q 5.2 | पृष्ठ २३२

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