What is the derivative of f(x)=e−2xf(x) = e^{-2x}f(x)=e−2x?
e−2xe^{-2x}e−2x
−2e−2x-2e^{-2x}−2e−2x
2e−2x2e^{-2x}2e−2x
−e−2x-e^{-2x}−e−2x