Miscellaneous
Last updated at August 17, 2026 by Teachoo
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