Question

What is the limit of `e^-x` as `x to oo` ?

Answer 1

As `x-> oo`, `y->0`

Explanation:

`e^-x=1/e^x`

When x grows infinitely large, the denominator grows infinitely large, causing y to approach 0, `y->0`.

Hence when `x->oo`, `y->0`

This is clearly visible when you graph the function, showing that is has a horizontal asymptote of `y=0`

graph{e^-x [-10, 10, -5, 5]}