Need help with solving for t value and plugging back into equation?

[itsgabriella]

1. An electron moving along the x-axis has a position given by x=16*te^-t m, where t is in seconds. How far is the electron from the origin when it momentarily stops?


2. Homework Equations
uv=u'v+uv'


3. The Attempt at a Solution
x'=e^-t - t*e^-t
e^-t - t*e^-t = 0
-te^-t = -e^-t
t = 1?

 

[tiny-tim]

welcome to pf!

hi itsgabriella! welcome to pf!

(try using the X² button just above the Reply box )

x'=e^-t - t*e^-t
e^-t - t*e^-t = 0
-te^-t = -e^-t
t = 1?

yup!

what's worrying you about that? ​