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(1+3^(1+n))/(1+3^n)

Limit of the function (1+3^(1+n))/(1+3^n)

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     /     1 + n\
     |1 + 3     |
 lim |----------|
n->oo|       n  |
     \  1 + 3   /
$$\lim_{n \to \infty}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right)$$
Limit((1 + 3^(1 + n))/(1 + 3^n), n, oo, dir='-')
Lopital's rule
We have indeterminateness of type
oo/oo,

i.e. limit for the numerator is
$$\lim_{n \to \infty}\left(3 \cdot 3^{n} + 1\right) = \infty$$
and limit for the denominator is
$$\lim_{n \to \infty}\left(3^{n} + 1\right) = \infty$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{n \to \infty}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right)$$
=
$$\lim_{n \to \infty}\left(\frac{\frac{d}{d n} \left(3 \cdot 3^{n} + 1\right)}{\frac{d}{d n} \left(3^{n} + 1\right)}\right)$$
=
$$\lim_{n \to \infty} 3$$
=
$$\lim_{n \to \infty} 3$$
=
$$3$$
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
Rapid solution [src]
3
$$3$$
Other limits n→0, -oo, +oo, 1
$$\lim_{n \to \infty}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = 3$$
$$\lim_{n \to 0^-}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = 2$$
More at n→0 from the left
$$\lim_{n \to 0^+}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = 2$$
More at n→0 from the right
$$\lim_{n \to 1^-}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = \frac{5}{2}$$
More at n→1 from the left
$$\lim_{n \to 1^+}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = \frac{5}{2}$$
More at n→1 from the right
$$\lim_{n \to -\infty}\left(\frac{3^{n + 1} + 1}{3^{n} + 1}\right) = 1$$
More at n→-oo
The graph
Limit of the function (1+3^(1+n))/(1+3^n)