# Ex 6.2, 1 - Chapter 6 Class 12 Application of Derivatives

Last updated at Jan. 7, 2020 by Teachoo

Last updated at Jan. 7, 2020 by Teachoo

Transcript

Ex 6.2, 1 (Method 1) Show that the function given by f (๐ฅ) = 3๐ฅ + 17 is strictly increasing on R. f(๐ฅ) = 3๐ฅ + 17 fโ(๐ฅ) = 3 Since fโ (๐ฅ) > 0 Hence, f is strictly increasing on R Ex 6.2, 1 (Method 2) Show that the function given by f (x) = 3x + 17 is strictly increasing on R. Let ๐ฅ1 and ๐ฅ2 be real numbers Such that ๐ฅ1 < ๐ฅ2 Multiplying both sides by 3 3๐ฅ1 < 3 ๐ฅ2 Adding both sides by 17 3๐ฅ1 + 17 < 3๐ฅ2 + 17 f (๐ฅ1) < f ( ๐ฅ2) Hence when x1 < x2 , f (x1) < f (x2) Thus, f(x) is strictly increasing on R.

Chapter 6 Class 12 Application of Derivatives

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