Subscribe to our Youtube Channel -

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


Misc 14 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): sin (x + a) Let f(x) = sin (x + a) Using sin (A + B) = sin A cos B + cos B sin A = sin x . cos a + cos x . sin a = cos a (sin x) + sin a (cos x) So, f’(x) = (cos a (sin x) + sin a (cos x))’ = (cos a (sin x))’ + (sin a (cos x))’ = cos a (sin x)’ + sin a (cos x)’ = cos a cos x + sin a ( – sin x) = cos a cos x – sin a sin x Derivative of sin x = cos x Derivative of cos x = – sin x = cos a cos x – sin a sin x = cos (a + x) = cos (x + a) Hence f’(x) = cos (x + a) Using cos (A + B) = cos A cos B – Sin A sin B

About the Author

Davneet Singh's photo - Teacher, Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.