I'll be studying engineering and am thinking I won't do too much in terms of analysis, unless of course I want to.
Another method in my text, which I somehow missed, was to take the ratio of A_n/A_(n+1) then simplify and take the limit as n approaches infinite. If the limit is infinite then...
Okay, that's some great knowledge that I can take forward. I'll just keep practicing on different problems and see what I get using what you showed me. Thanks!
Okay. I think I'm starting to see something, but am unsure if what I did was correct.
((n+1)n!)2/(2n+2)(2n+1)(2n) = (n!)2/(2n!)
((n+1)n!)2/(n!)2 = (2n+2)(2n+1)(2n!)/(2n!)
(n+1)2 = (2n+2)(2n+1)
n2+2n+1/4n2+5n+2 = 1
I see that the denominator is greater from here and this will be...
Hey Mr. Anchovy,
I stumbled upon what it expands to,
(2n)! = 2ⁿ*(n!)*[ 1.3.5...(2n-1) ]
And see hows it's decreasing.
But how (2n)! expands out to that, seems unintuitive at this point.
Using An+1 = ((n+1)!)^2/(2n+2)! Which still leaves me lost. I feel like I just don't understand...
Homework Statement
These trickly little buggers always seem to confuse me. I need to find out whether or not the sequence is increasing, decreasing or neither.
An=(n!)2/(2n)!
Homework Equations
The Attempt at a Solution
I'm pretty sure that it's a decreasing sequences but when I expand and...
Gotcha,
##a_0=\frac 1 {2}^{1}##
##a_1=\frac 1 {2}^{2}##
##a_2=\frac 1 {2}^{4}##
##a_3=\frac 1 {2}^{8}##
Bingo. ##a_n={2}^{2}^{n}##
I can't seem to get latex to work but it's 22n
EDIT: I got excited, it's 1/22n
##a_1##=##(0.5)^2##
##a_2##=##(0.25)^2##
##a_3##=##(0.0625)^2##
##a_4##=##(0.00390625)^2##
Hmmm, I see that 0625 is recurring and I'm assuming that as n increases, the amount of decimal places increase by 2n places. Does that make sense?
EDIT: This is probably what you didn't want me to do...
I'm sort of confused where the 4 came from. Is that just the result of pairing up the first 2, then showing the third 2 term as 2n-2?
4 \frac{n}{(n-1)} \frac{2^{n-2}}{(n-2)!} This is what I get after cancelling n's. But as to show how this approaches 0, I'm totally lost.
Homework Statement
A bored student enters the number 0.5 in her calculator, then repeatedly computes the square of the number in the display. Taking A0 = 0.5, find a formula for the general term of the sequence {An} of the numbers that appear in the display, and find the limit of the sequence...
Homework Statement
Find the limit of n22n/(n!)
Homework Equations
The Attempt at a Solution
First I expand out 2n/(n!) = (2/1)(2/2)(2/3)(2/4)...(2/n) which gets increasingly small as n increases. Now, where does the n2 fit into this? I know the limit to be 0 but I can't get...