Question
cos(a cos x + b sin x), for some constant a and b.
cos(a cos x + b sin x), for some constant a and b.
Let y $=$ cos (a cos x + b sin x) ...(i)
Differentiating (i) on both sides w.r.t. x, we get
$\cfrac{{dy}}{{dx}} = -$ sin (a cos x + b sin x) [a ($-$sin x) + b cos x]
$= -$ sin (a cos x + b sin x) [$-$a sin x + b cos x]
$=$ (a sin x$-$ b cos x) sin (a cos x + b sin x)
NCERT & Exemplar solution for CBSE Class 12 Mathematics, Continuity and Differentiability. Curated by Sachin Sharma. Free for all students.