Hey

Can someone help with finding the derivative of y = xe^(-x/2)

You are dealing with a formula of type f(x) = f1(x) * f2(x)
In your example, f1(x) = x and f2(x) = e^(-x/2)
Basic formula is f'(x) = ( f1(x) * f2(x) )' = f1'(x)*f2(x) + f1(x)*f2'(x)
f1'(x) = 1
f2'(x) = -(1/2)*e^(-x/2)

So that means that f'(x) = 1*e^(-x/2) + x*(-(1/2))*e^(-x/2) = e^(-x/2)*(1 - (1/2)*x)

Thanks... I ended up working it out. Though me and a friend are stuck on trying to sketch it

Calc101.com

HANK :confused: