# Ex 6.5, 4 (iii) - Chapter 6 Class 12 Application of Derivatives (Term 1)

Last updated at Aug. 19, 2021 by

Last updated at Aug. 19, 2021 by

Transcript

Ex 6.5, 4 Prove that the following functions do not have maxima or minima: (iii) β(π₯)= π₯^3+π₯^2+π₯+1Given h (x) = x3 + x2 + x + 1 Finding maxima or minima ββ (π₯) = 3π₯^2+2π₯+1 Putting ββ (π₯)= 0 3π₯^2+2π₯+1=0 For ax2 + bx + c = 0 x = (βπ Β± β(π^2 β 4ππ))/2π Here π = 3, b = 2, & c = 1 x = (β 2 Β± β(4 β 4(3)(1)))/6 x = (β 2 Β± β(4 β 12))/6 x = (β2 Β± β(β 8))/6 x = (β 2 Β± 2β(β 2))/6 x = (βπ Β± β(β π))/π Since root has minus sign, x has no real value β΄ h (x) does not have a maxima of minima

Ex 6.5

Ex 6.5, 1 (i)
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Ex 6.5, 1 (ii)

Ex 6.5, 1 (iii) Important

Ex 6.5, 1 (iv)

Ex 6.5, 2 (i)

Ex 6.5, 2 (ii) Important

Ex 6.5, 2 (iii)

Ex 6.5, 2 (iv) Important

Ex 6.5, 2 (v) Important

Ex 6.5, 3 (i)

Ex 6.5, 3 (ii)

Ex 6.5, 3 (iii)

Ex 6.5, 3 (iv) Important

Ex 6.5, 3 (v)

Ex 6.5, 3 (vi)

Ex 6.5, 3 (vii) Important

Ex 6.5, 3 (viii)

Ex 6.5, 4 (i)

Ex 6.5, 4 (ii) Important

Ex 6.5, 4 (iii) You are here

Ex 6.5, 5 (i)

Ex 6.5, 5 (ii)

Ex 6.5, 5 (iii) Important

Ex 6.5, 5 (iv)

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Ex 6.5, 27 (MCQ)

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Ex 6.5,29 (MCQ)

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