- #1
physics604
- 92
- 2
Homework Statement
Find the derivative of y=xe-kx
Homework Equations
Chain rule
The Attempt at a Solution
y = xeu
[itex]\frac{dy}{du}[/itex] = xeu+eu
u = -kx
[itex]\frac{du}{dx}[/itex] = -k
[itex]\frac{dy}{dx}[/itex] = (xe-kx+e-kx)(-k)
= e-kx(x+1)(-k)
= e-kx(-kx-k)
The answer is e-kx(-kx+1). What did I do wrong?