Problemddx(xcosx)\frac{d}{dx}(x \cos x)dxd(xcosx)단계별 풀이(fg)′=f′g+fg′(fg)' = f'g + fg'(fg)′=f′g+fg′ 를 f=xf = xf=x, g=cosxg = \cos xg=cosx 에 적용합니다.f′=1f' = 1f′=1, g′=−sinxg' = -\sin xg′=−sinx.결과: cosx−xsinx\cos x - x\sin xcosx−xsinx.답cos(x)−xsin(x)\cos(x) - x\sin(x)cos(x)−xsin(x)다른 문제를 풀고 싶으신가요? derivative 풀기 →관련 예제/solve/calculus/derivative-of-cos-x더 읽기/blog/chain-rule-mastery