Misc 23 - Find derivative: (x2 + 1) cos x - Class 11 NCERT - Derivatives by formula - sin & cos

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  1. Chapter 13 Class 11 Limits and Derivatives
  2. Serial order wise

Transcript

Misc 23 Find the derivative of the following functions (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers): (x2 + 1) cos x Let f (x) = (x2 + 1) cos x Let u = (x2 + 1) & v = cos x f(x) = uv So, f (x) = Using product rule f (x) = + Finding u & v u = x2 + 1 u = 2. x2 1 + 0 = 2x & v = cos x v = sin x Now, f (x) = = + = 2x ( cos x) + ( sin x) (x2 + 1) = 2x cos x sin x (x2 + 1) = 2x cos x2 sin x sin x = x2 sin x sin x + 2x cos x

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Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.