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Ex 6.2, 12 (B) - Chapter 6 Class 12 Application of Derivatives (Term 1)
Last updated at Aug. 19, 2021 by Teachoo
Transcript
Ex 6.2, 12 Which of the following functions are strictly decreasing on (0,π/2) ? (B) cos 2π₯ Let f(π₯) = cos 2π₯ Finding fβ(π) fβ(π₯) = (cosβ‘2π₯ )β² fβ(π₯) = β2 sin 2π₯ Let 2π₯ = ΞΈ β΄ fβ(π₯) = β2 sin ΞΈ When 0 < x < π/2 , then 0 < ΞΈ < π Since sin ΞΈ > 0 for 0 < ΞΈ < π Therefore, sin 2x > 0 for 0 < 2x < π Multiplying β2 both sides β2 Γ sin 2x < β2 Γ 0 for 0 < 2x < π β2 sin 2x < 0 for 0 < 2x < π fβ(x) < 0 for 0 < 2x < π fβ(x) < 0 for 0 < x < π /π Therefore, f(x) is strictly decreasing for π β (π , π /π)
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Ex 6.2
Ex 6.2, 1
Ex 6.2,2
Ex 6.2,3
Ex 6.2,4
Ex 6.2, 5
Ex 6.2, 6 (a)
Ex 6.2, 6 (b)
Ex 6.2, 6 (c)
Ex 6.2, 6 (d)
Ex 6.2, 6 (e) Important
Ex 6.2, 7
Ex 6.2,8 Important
Ex 6.2,9 Important
Ex 6.2,10
Ex 6.2,11
Ex 6.2, 12 (A)
Ex 6.2, 12 (B) Important You are here
Ex 6.2, 12 (C) Important
Ex 6.2, 12 (D)
Ex 6.2, 13 (MCQ) Important
Ex 6.2,14 Important
Ex 6.2,15
Ex 6.2, 16
Ex 6.2,17 Important
Ex 6.2,18
Ex 6.2,19 (MCQ) Important
Chapter 6 Class 12 Application of Derivatives (Term 1)
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