What is the Limit of e^(1/x) as x Approaches 0 and the Direction Matters?

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SUMMARY

The limit of e^(1/x) as x approaches 0 depends on the direction of the approach. When approaching from the left (b -> 0-), 1/b tends to negative infinity, leading to the limit of e^(1/x) approaching 0. Conversely, when approaching from the right (x -> 0+), the limit diverges to positive infinity, as indicated by the expression lim_{x -> 0+} e^(1/x) = +∞. The discussion highlights the importance of direction in evaluating limits involving exponential functions.

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Phys12
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1cbf4ac287084491ad5b7ed95f9ed522.jpg

In this solution, in the last 3rd line, I get the first part (-e^-1 - e^-1), however, after the '-' symbol, the person writes (1/b * e^1/b - e^1/b) and takes the limit as b->0. However, shouldn't this give him (inf. * e^inf - e^inf)?

Thanks
(His answer is correct, by the way)
 
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Phys12 said:
1cbf4ac287084491ad5b7ed95f9ed522.jpg

In this solution, in the last 3rd line, I get the first part (-e^-1 - e^-1), however, after the '-' symbol, the person writes (1/b * e^1/b - e^1/b) and takes the limit as b->0. However, shouldn't this give him (inf. * e^inf - e^inf)?

Thanks
(His answer is correct, by the way)
b approaches 0 from below, so 1/b tends to minus infinity. There is a small mistake: the 1 in the (1 . 0 - 0) term. Need to use the fact that x e-x tends to 0 as x tends to +infinity.
 
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haruspex said:
b approaches 0 from below, so 1/b tends to minus infinity. There is a small mistake: the 1 in the (1 . 0 - 0) term. Need to use the fact that x e-x tends to 0 as x tends to +infinity.
Ohk! I didn't notice the fact that we were approaching 0 from the left hand side. Thanks! :)
 
Phys12 said:
Ohk! I didn't notice the fact that we were approaching 0 from the left hand side. Thanks! :)

Right: if you approach 0 from the right the function blows up: ##\lim_{x \to 0+} e^{1/x} = +\infty##.
 

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