Mister Exam
Other calculators:
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How to use it?
- Limit of the function:
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Limit of (1-cos(x)^2)/x
-
Limit of (1-cos(4*x))/(4*x^2)
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Limit of (1+8*x)^(1/x)
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Limit of (1+7/x)^(3*x)
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Identical expressions
- (one + seven /x)^(three *x)
- (1 plus 7 divide by x) to the power of (3 multiply by x)
- (one plus seven divide by x) to the power of (three multiply by x)
- (1+7/x)(3*x)
- 1+7/x3*x
- (1+7/x)^(3x)
- (1+7/x)(3x)
- 1+7/x3x
- 1+7/x^3x
- (1+7 divide by x)^(3*x)
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Similar expressions
- (1-7/x)^(3*x)
Limit of the function (1+7/x)^(3*x)
The solution
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3*x
/ 7\
lim |1 + -|
x->oo\ x/
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x}$$
Limit((1 + 7/x)^(3*x), x, oo, dir='-')
Detail solution
Let's take the limit
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x}$$
transform
do replacement
$$u = \frac{x}{7}$$
then
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x}$$ =
=
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{21 u}$$
=
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{21 u}$$
=
$$\left(\left(\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}\right)\right)^{21}$$
The limit
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}$$
is second remarkable limit, is equal to e ~ 2.718281828459045
then
$$\left(\left(\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}\right)\right)^{21} = e^{21}$$
The final answer:
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x} = e^{21}$$
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x}$$
transform
do replacement
$$u = \frac{x}{7}$$
then
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x}$$ =
=
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{21 u}$$
=
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{21 u}$$
=
$$\left(\left(\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}\right)\right)^{21}$$
The limit
$$\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}$$
is second remarkable limit, is equal to e ~ 2.718281828459045
then
$$\left(\left(\lim_{u \to \infty} \left(1 + \frac{1}{u}\right)^{u}\right)\right)^{21} = e^{21}$$
The final answer:
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x} = e^{21}$$
Lopital's rule
There is no sense to apply Lopital's rule to this function since there is no indeterminateness of 0/0 or oo/oo type
The graph
Other limits x→0, -oo, +oo, 1
$$\lim_{x \to \infty} \left(1 + \frac{7}{x}\right)^{3 x} = e^{21}$$
$$\lim_{x \to 0^-} \left(1 + \frac{7}{x}\right)^{3 x} = 1$$
More at x→0 from the left
$$\lim_{x \to 0^+} \left(1 + \frac{7}{x}\right)^{3 x} = 1$$
More at x→0 from the right
$$\lim_{x \to 1^-} \left(1 + \frac{7}{x}\right)^{3 x} = 512$$
More at x→1 from the left
$$\lim_{x \to 1^+} \left(1 + \frac{7}{x}\right)^{3 x} = 512$$
More at x→1 from the right
$$\lim_{x \to -\infty} \left(1 + \frac{7}{x}\right)^{3 x} = e^{21}$$
More at x→-oo
$$\lim_{x \to 0^-} \left(1 + \frac{7}{x}\right)^{3 x} = 1$$
More at x→0 from the left
$$\lim_{x \to 0^+} \left(1 + \frac{7}{x}\right)^{3 x} = 1$$
More at x→0 from the right
$$\lim_{x \to 1^-} \left(1 + \frac{7}{x}\right)^{3 x} = 512$$
More at x→1 from the left
$$\lim_{x \to 1^+} \left(1 + \frac{7}{x}\right)^{3 x} = 512$$
More at x→1 from the right
$$\lim_{x \to -\infty} \left(1 + \frac{7}{x}\right)^{3 x} = e^{21}$$
More at x→-oo
The graph