
Miscellaneous
Last updated at December 16, 2024 by Teachoo
Transcript
Misc 13 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): (ax + b)n (cx + d)m Let f(x) = (ax + b)n (cx + d)m Let u = (ax + b)n & v = (cx + d)m f(x) = uv So, f (x) = (uv) f (x) = u v + v u Finding u & v u = (ax + b)n u = an (ax + b)n 1 v = (cx + d)m v = cm (cx + d)m 1 f (x) = (uv) = u v + v u = an (ax + b)n 1(cx + d)m + cm(cx + d)m 1 (ax + b)n = an (ax + b)n 1(cx + d)m 1 (cx + d) + cm (cx + d)m 1(ax + b)n 1 (ax + b) = (ax + b)n 1(cx + b)m 1 (an (cx + d)+ cm (ax + b)) = (ax + b)n 1(cx + b)m 1 (an (cx + d)+ mc (ax + b))