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(-1+e^(-x))/x

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

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The solution

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     /      -x\
     |-1 + E  |
 lim |--------|
x->0+\   x    /
$$\lim_{x \to 0^+}\left(\frac{-1 + e^{- x}}{x}\right)$$
Limit((-1 + E^(-x))/x, x, 0)
Lopital's rule
We have indeterminateness of type
0/0,

i.e. limit for the numerator is
$$\lim_{x \to 0^+}\left(1 - e^{x}\right) = 0$$
and limit for the denominator is
$$\lim_{x \to 0^+}\left(x e^{x}\right) = 0$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to 0^+}\left(\frac{-1 + e^{- x}}{x}\right)$$
=
Let's transform the function under the limit a few
$$\lim_{x \to 0^+}\left(\frac{\left(1 - e^{x}\right) e^{- x}}{x}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(1 - e^{x}\right)}{\frac{d}{d x} x e^{x}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{e^{x}}{x e^{x} + e^{x}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{1}{x e^{x} + e^{x}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{1}{x e^{x} + e^{x}}\right)$$
=
$$-1$$
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
$$\lim_{x \to 0^-}\left(\frac{-1 + e^{- x}}{x}\right) = -1$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(\frac{-1 + e^{- x}}{x}\right) = -1$$
$$\lim_{x \to \infty}\left(\frac{-1 + e^{- x}}{x}\right) = 0$$
More at x→oo
$$\lim_{x \to 1^-}\left(\frac{-1 + e^{- x}}{x}\right) = - \frac{-1 + e}{e}$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(\frac{-1 + e^{- x}}{x}\right) = - \frac{-1 + e}{e}$$
More at x→1 from the right
$$\lim_{x \to -\infty}\left(\frac{-1 + e^{- x}}{x}\right) = -\infty$$
More at x→-oo
Rapid solution [src]
-1
$$-1$$
One‐sided limits [src]
     /      -x\
     |-1 + E  |
 lim |--------|
x->0+\   x    /
$$\lim_{x \to 0^+}\left(\frac{-1 + e^{- x}}{x}\right)$$
-1
$$-1$$
= -1.0
     /      -x\
     |-1 + E  |
 lim |--------|
x->0-\   x    /
$$\lim_{x \to 0^-}\left(\frac{-1 + e^{- x}}{x}\right)$$
-1
$$-1$$
= -1.0
= -1.0
Numerical answer [src]
-1.0
-1.0
The graph
Limit of the function (-1+e^(-x))/x