Find f′(x)f'(x)f′(x) for f(x)=sin(e−x)f(x) = \sin(e^{-x})f(x)=sin(e−x).
−cos(e−x)e−x-\cos(e^{-x}) e^{-x}−cos(e−x)e−x
cos(e−x)e−x\cos(e^{-x}) e^{-x}cos(e−x)e−x
−sin(e−x)-\sin(e^{-x})−sin(e−x)
0