y = (2x)/(x+1) When solving for the horizontal asymptote and substituting infinity in for x, infinity just crosses out and i'm left with 2/1 making the horizontal asymptote y = 2. right?
You say you cannot substitute infinity because it is not a number. But my teacher has said on several occassions it is a number but not a measurable one. But when infinity is in the denominator of any equation example : 6/infinity that is 0. So perhaps I just understood you wrong.
No, you have understood me perfectly. Infinity is not a number and cannot be substituted into an expression. To do so is sloppy and mathematically wrong.
When dealing with infinity, you have to take a limit. 6/infinity = 0 is a complete nonsense, is the correct way of treating it.