Problem with Limits; basic calculus
- To: mathgroup at smc.vnet.net
- Subject: [mg38952] Problem with Limits; basic calculus
- From: sophtwarez at hotmail.com (David Seruyange)
- Date: Tue, 21 Jan 2003 07:39:46 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hey all - I'm taking a basic calculus course that uses Mathematica. We have been studying limits and I have been using the Limit function to check if my answers are correct. We were given the following function and asked to determine a limit: (3E^(-x) - E^(-3x)) / (E^(-3x) + E^(-x)) Usually the approach is to select the dominant terms, factor and then determine the limit. My initial reason had me select -E^(-3x) in the numerator and E^(-3x) in the denominator. Factoring the terms would yield -1, thus the limit for x->infinity. But I plotted the function and the real answer is somewhere near 3. I then tried to use the Limit function which is not producing an answer (perhaps I'm not sure of the usage). Any help is greatly appreciated, David Seruyange