Question

Limit of x^3*exp^(-x) as x goes to infinity and -infinity ... ! i don't really understand to do this ? is it OK to say that the exponent is "winning" in going to infinity ?

Answer 1

What do you mean by "exp^(-x)" ?

Answer 2

\[x^3 ex^{-x}\]

Answer 3

??

Answer 4

no \[x ^{3} e ^{-x}\]

Answer 5

thanks ! =)

Answer 6

Rewrite e^-x.

Answer 7

\[a^{-n} = \frac{1}{a^n}\]

Answer 8

yes, but still .. i can't use lhopital !!!

Answer 9

Well what happens as e^x approaches infinity?

Answer 10

so i have infinity over infinity ! GOOD !

Answer 11

you don't use a carrot with the \(\exp(\cdot)\) notation

\[\exp(x)=e^{x}\]