Quick Deriv. Question

[CFABLACKBELT]

Hey guys, my first post here. I can't seem to figure out this calc. question. Or more how the answer was obtained. Thanks.

Differentiate: xe^(-kx)


Answer (highlight to see): e^(-kx)*(-kx+1)

 

[kirylm]

check here: Product rule - Wikipedia, the free encyclopedia
((xe^{-kx})' = (x)'*(e^{-kx}) + x*(e^{-kx})' = 1*e^{-kx} + x*(-kx)'*e^{-kx} = e^{-kx} + x*(-k)*e^{-kx} = e^{-kx} - xke^{-kx}=e^{-kx}(1-xk))

 

[Uncle Max]

At first I couldn't understand how is this question related to "derivatives". Then it striked me that it's about mathematical derivatives. Too much Finance for me

 

[Pulco]

I bet you are not a quant CFABLACKBELT ?