Find the intervals in which `f(x)=(x+2)e^(-x)` is increasing or decreasing.

Explanation

We have given

`f(x)=(x+2)e^(-x)`

Then we have to find: Intervals at which `f(x)` is increasing on decreasing

`f(x)=(x+2)e^(-x)`

`f'(x)=(1)e^(-x)+(x+2)(-e^(-x))`

`=e^(-x)[1−x−2]`

`=e^(-x)[−x-1]`

`=-e^(-x)(1+x)`

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