Chapter 3 - Section 3.3 - Derivatives of Trigonometric Functions - 3.3 Exercises - Page 196: 2

$f'(x)=-x\sin x+\cos x+2\sec^{2}x$

$f(x)=x\cos x+2\tan x$ Differentiate each term: $f'(x)=(x\cos x)'+(2\tan x)'=...$ Use the product rule to differentiate $x\cos x$ $...=(x)(\cos x)'+(\cos x)(x)'+2\sec^{2}x=...$ $...=-x\sin x+\cos x+2\sec^{2}x$