How do you differentiate #f(x) = e^-x sinx-e^xcosx#?

1 Answer
Nov 11, 2015

#f'(x)=(e^{x}-e^{-x})(sin(x)-cos(x))#

Explanation:

#f'(x)=frac{d}{dx}(e^{−x}sin(x)−e^xcos(x))#

#=frac{d}{dx}(e^{−x}sin(x))−frac{d}{dx}(e^xcos(x))#

#=[e^{−x}frac{d}{dx}(sin(x))+sin(x)frac{d}{dx}(e^{−x})]#

#−[e^xfrac{d}{dx}(cos(x))+cos(x)frac{d}{dx}(e^x)]#

#=[e^{−x}(cos(x))+sin(x)(-e^{−x})]#

#−[e^x(-sin(x))+cos(x)(e^x)]#

#=e^{−x}(cos(x)-sin(x))-e^x(cos(x)-sin(x))#

#=(e^{−x}-e^{x})(cos(x)-sin(x))#