![Misc 25 - Chapter 13 Class 11 Limits and Derivatives - Part 2](https://cdn.teachoo.com/6d239a43-a5a4-46ba-b2c3-720da6eeb138/slide72.jpg)
Miscellaneous
Last updated at Dec. 16, 2024 by Teachoo
Misc 25 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): (x + cos x) (x tan x) Let f (x) = (x + cos x) (x tan x) Let u = x + cos x & v = x tan x f(x) = uv So, f (x) = Using product rule f (x) = + Finding u & v u = x + cos x u = (x + cos x) = 1 sin x & v = x tan x v = (x tan x) = 1 sec2 x Now, f (x) = = + = (1 sin x) (x tan x) + (1 sec2 x) (x + cos x) = (1 sin x) (x tan x) (sec2 x 1) (x +cos x) = (1 sin x) (x tan x) tan2x (x + cos x) = tan2x (x + cos x) + (x tan x) (1 sin x)