A _______________________ is a comparison of two measurements in which the denominator has a value of one unit.

Consider the series ∑n=1[infinity]2nn!nn. Evaluate the the following limit. If it is infinite, type "infinity" or "inf". If it d

Vikki [24]

I guess the series is

$\displaystyle\sum_{n=1}^\infty\frac{2^nn!}{n^n}$

We have

$\displaystyle\lim_{n\to\infty}\left|\frac{\frac{2^{n+1}(n+1)!}{(n+1)^{n+1}}}{\frac{2^nn!}{n^n}}\right|=2\lim_{n\to\infty}\left(\frac n{n+1}\right)^n$

Recall that

$e=\displaystyle\lim_{n\to\infty}\left(1+\frac1n\right)^n$

In our limit, we have

$\dfrac n{n+1}=\dfrac{n+1-1}{n+1}=1-\dfrac1{n+1}$

$\left(\dfrac n{n+1}\right)^n=\dfrac{\left(1-\frac1{n+1}\right)^{n+1}}{1-\frac1{n+1}}$

$\implies\displaystyle2\lim_{n\to\infty}\left(\frac n{n+1}\right)^n=2\frac{\lim\limits_{n\to\infty}\left(1-\frac1{n+1}\right)^{n+1}}{\lim\limits_{n\to\infty}\left(1-\frac1{n+1}\right)}=\frac{2e}1=2e$

which is greater than 1, which means the series is divergent by the ratio test.

On the chance that you meant to write

$\displaystyle\sum_{n=1}^\infty\frac{2^n}{n!n^n}$

we have

$\displaystyle\lim_{n\to\infty}\left|\frac{\frac{2^{n+1}}{(n+1)!(n+1)^{n+1}}}{\frac{2^n}{n!n^n}}\right|=2\lim_{n\to\infty}\frac1{(n+1)^2}\left(\frac n{n+1}\right)^2$

$=\displaystyle2\left(\lim_{n\to\infty}\frac1{(n+1)^2}\right)\left(\lim_{n\to\infty}\left(\frac n{n+1}\right)^n\right)=2\cdot0\cdot e=0$

which is less than 1, so this series is absolutely convergent.

6 0

3 years ago

Scott and Mark are going to see a movie. The clocks show when the movie begins and ends.

Montano1993 [528]

The elapsed time is B, 2 hours and 25 minutes.

3 0

3 years ago

Read 2 more answers

write an equation in slop-intercept form for a line that is perpendicular to the line y= -5x-3 and has a y-intercept of 6.

jenyasd209 [6]

Answer:

The equation of the line would be y = 1/5x + 6

Step-by-step explanation:

First, to find the slope of a perpendicular line, you need to find the opposite and reciprocal of the original slope. Since the original is -5, we first change the sign (which makes it just 5). Now we take that 5 and flip it to get 1/5.

Now that we have the slope as 1/5, we can use that and the intercept in slope-intercept form to get the equation.

y = mx + b

y = 1/5x + 6

6 0

3 years ago

What are two expressions that are equivalent to 6(5j + 2 + j)?

ziro4ka [17]

Answer:

1. 30j+12+6j

2. 36j+12

3. 6(6j+2)

Step-by-step explanation:

1. You just multiply so... 6x5j ... 6x2 ... 6xj

2. you multiply and then simplify so first you have 30j+12+6j, so you add like terms so... 30j+6j= 36j and then +12

3. you do what's in the parentheses first so 5j+j=6j so .... 6(6j+2)

5 0

4 years ago

HELP MEEEEEEEEEEEE (please don't put a link or i don't know)

Leviafan [203]

Answer:

42 i think

Step-by-step explanation:

7 0

3 years ago