# I'm stumped about solving limits at infinity

• Nov 18th 2008, 08:41 AM
aliveiam
I'm stumped about solving limits at infinity
I don't see how any of the rules about the powers in the numerator and the denominator would apply to this problem:

limit (as x approaches infinity) of x / e^x

The power of the numerator is 1, but how does one evaluate the power of the denominator if it is a variable?

Thanks again for any support. This forum is great.
• Nov 18th 2008, 09:11 AM
dolphinlover
Quote:

Originally Posted by aliveiam
I don't see how any of the rules about the powers in the numerator and the denominator would apply to this problem:

limit (as x approaches infinity) of x / e^x

The power of the numerator is 1, but how does one evaluate the power of the denominator if it is a variable?

Thanks again for any support. This forum is great.

Have u heard of L"Hospitals Rule for limits? The limit (as x approaches infinity) of x is infinity and the limit of e^x ( as x approaches infinity) is also zero. So this limit is infinity/infinity...which is where you use L'Hospitals Rule (which in this case look at the powers in both numerator & denominator)