Why is it that lim x->∞ while lim x->-∞ ∞? They both simplify to the same function but one gives a numerical value while the other one doesn't.
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Originally Posted by Barthayn Why is it that lim x->∞ while lim x->-∞ ∞? They both simplify to the same function but one gives a numerical value while the other one doesn't. First a correction: let then . Question: Have you graphed the function? Do you see that What does the sign of when tell you?
Last edited by Plato; Nov 29th 2011 at 01:50 PM.
Hello, Barthayn! I don't understand your problem. I get only one answer. . . . We have: . Multiply by . . Divide numerator and denominator by . . . . Therefore: .
Originally Posted by Soroban Hello, Barthayn! I don't understand your problem. I get only one answer. We have: . Multiply by . . Divide numerator and denominator by . . Not if x<0, because then ! . . Therefore: . The answer x=–1 is correct, of course, for the limit as , but not for the limit as . ..
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