# Ex 6.2,13 - Chapter 6 Class 12 Application of Derivatives

Last updated at Dec. 14, 2019 by Teachoo

Last updated at Dec. 14, 2019 by Teachoo

Transcript

Ex 6.2,13 On which of the following intervals is the function f given by f ( ) = 100 + sin 1 strictly decreasing ? (A) (0,1) (B) 2 , (C) 0, 2 (D) None of these f (x) = 100 + sin x 1 f (x) = 100 99 + cos x (A) (0, 1) For 0 < x < 1 So, 100 x99 + cos x is positive. f (x) > 0 f (x) is increasing on (0, 1) (B) , 2 < x < 1.57 < x < 3.14 Since 100 x99 is much greater than 1 So 100 x99 + cos x is positive f (x) > 0 , 0< < 2 So 100 x99 + cos x is positive f (x) > 0 f(x) is increasing on 0, 2 f(x) is strictly decreasing for none of the intervals. So (D) is the correct answer

Chapter 6 Class 12 Application of Derivatives

Serial order wise

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