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Prove that the following function do not have maxima or minima: h(x) = x3 + x2 + x + 1

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प्रश्न

Prove that the following function do not have maxima or minima:

h(x) = x3 + x2 + x + 1

योग
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उत्तर

Given function, h(x) = x3 + x2 + x + 1

∴ h'(x) = 3x2 + 2x + 1 x ∈ R.

if, 3x2 + 2x + 1 = 0 then,

x `= (-2 pm sqrt(4 - 12))/6`

x `= (-2 pm sqrt(-8))/6`

`= (-1 pm sqrt (-2))/3`       ...[which is non-real]

For x ∈ R, h'(x) ≠ 0

Hence there is no highest or lowest value of h.

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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 4.3 | पृष्ठ २३२

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