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2*x/(1+x)

Limit of the function 2*x/(1+x)

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     / 2*x \
 lim |-----|
x->oo\1 + x/
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right)$$
Limit((2*x)/(1 + x), x, oo, dir='-')
Detail solution
Let's take the limit
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right)$$
Let's divide numerator and denominator by x:
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right)$$ =
$$\lim_{x \to \infty}\left(\frac{2}{1 + \frac{1}{x}}\right)$$
Do Replacement
$$u = \frac{1}{x}$$
then
$$\lim_{x \to \infty}\left(\frac{2}{1 + \frac{1}{x}}\right) = \lim_{u \to 0^+}\left(\frac{2}{u + 1}\right)$$
=
$$\frac{2}{1} = 2$$

The final answer:
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right) = 2$$
Lopital's rule
We have indeterminateness of type
oo/oo,

i.e. limit for the numerator is
$$\lim_{x \to \infty}\left(2 x\right) = \infty$$
and limit for the denominator is
$$\lim_{x \to \infty}\left(x + 1\right) = \infty$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right)$$
=
Let's transform the function under the limit a few
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} 2 x}{\frac{d}{d x} \left(x + 1\right)}\right)$$
=
$$\lim_{x \to \infty} 2$$
=
$$\lim_{x \to \infty} 2$$
=
$$2$$
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
$$\lim_{x \to \infty}\left(\frac{2 x}{x + 1}\right) = 2$$
$$\lim_{x \to 0^-}\left(\frac{2 x}{x + 1}\right) = 0$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(\frac{2 x}{x + 1}\right) = 0$$
More at x→0 from the right
$$\lim_{x \to 1^-}\left(\frac{2 x}{x + 1}\right) = 1$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(\frac{2 x}{x + 1}\right) = 1$$
More at x→1 from the right
$$\lim_{x \to -\infty}\left(\frac{2 x}{x + 1}\right) = 2$$
More at x→-oo
Rapid solution [src]
2
$$2$$
The graph
Limit of the function 2*x/(1+x)