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e^x/(1+e^x)

Limit of the function e^x/(1+e^x)

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     /   x  \
     |  E   |
 lim |------|
x->oo|     x|
     \1 + E /
$$\lim_{x \to \infty}\left(\frac{e^{x}}{e^{x} + 1}\right)$$
Limit(E^x/(1 + E^x), x, oo, dir='-')
Lopital's rule
We have indeterminateness of type
oo/oo,

i.e. limit for the numerator is
$$\lim_{x \to \infty} e^{x} = \infty$$
and limit for the denominator is
$$\lim_{x \to \infty}\left(e^{x} + 1\right) = \infty$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to \infty}\left(\frac{e^{x}}{e^{x} + 1}\right)$$
=
Let's transform the function under the limit a few
$$\lim_{x \to \infty}\left(\frac{e^{x}}{e^{x} + 1}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} e^{x}}{\frac{d}{d x} \left(e^{x} + 1\right)}\right)$$
=
$$\lim_{x \to \infty} 1$$
=
$$\lim_{x \to \infty} 1$$
=
$$1$$
It can be seen that we have applied Lopital's rule (we have taken derivatives with respect to the numerator and denominator) 1 time(s)
The graph
Other limits x→0, -oo, +oo, 1
$$\lim_{x \to \infty}\left(\frac{e^{x}}{e^{x} + 1}\right) = 1$$
$$\lim_{x \to 0^-}\left(\frac{e^{x}}{e^{x} + 1}\right) = \frac{1}{2}$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(\frac{e^{x}}{e^{x} + 1}\right) = \frac{1}{2}$$
More at x→0 from the right
$$\lim_{x \to 1^-}\left(\frac{e^{x}}{e^{x} + 1}\right) = \frac{e}{1 + e}$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(\frac{e^{x}}{e^{x} + 1}\right) = \frac{e}{1 + e}$$
More at x→1 from the right
$$\lim_{x \to -\infty}\left(\frac{e^{x}}{e^{x} + 1}\right) = 0$$
More at x→-oo
Rapid solution [src]
1
$$1$$
The graph
Limit of the function e^x/(1+e^x)