series questions
@amistre64
the integral test is pretty much change n to x and integrate
n^4/n^6, since the bottom is bigger degree than top, the sequence an goes to zero
cant say i know what tests to choose tho :/
so 5 converges right and what is the test you used?
5 converges and the limit of an IS 0, but yeah, i got no solid on the tests used.
do you know anyone who can help me with this? I really dont know how to do this.
the next one, a test cant converge and diverge at the same time; and a test will either be converge, diverge, or inconclusive
I just tried that and its wrong.
which one you try?
number 6
yeah, which option?
2nd option
why?
i said: a test cant converge and diverge at the same time; and a test will either be converge, diverge, or inconclusive
you said the series converges and diverges at the saem time right
oh sorry I read that wrong
so which option is it?
it can be more than one
a little self reflection here. ive given ample hints for it :)
you said it can either converge diverge or be inconclusive. However I dont think the first option is right since comparision test doesnt take precedence so is it option 4
option 4 is what im thinking, the analysis is in errorsince one test says converge, the other says diverge
3 may be plausible, but i dont think its the most accurate
it may be possible to determine if the analysis is done correctly
4 is correct.
yay!! :)
do you know how to get the associated function for 3?
i believe, like i posted, change n to x
do I need to add +C to the answer?
no, its asking for the function that gets integrated, not for the integration itself
\[\sum f(n)\to\int f(x)\]
I did that and I got it wrong I got 1/2tan^-1(x)^2
f(x) is more compact; if it converges then the f(n) would have to converge as well
\[\frac{tan^{-1}(x)}{x^2+1}\]
yeah I took the indefinite integral of that
it doesnt ask you to do that
what does it ask then?
it asks what function of x you would use to integrate ....
Ok I understand now.
for example:\[\sum n^2\to\int x^2~dx\] f(n) = n^2; f(x) = x^2
ok here is another problem I dont get
id suggest doing a root test on it
it converges
lim |n^(2/n) pi/4 |
the limit is about 3/4 right?
no its 0
http://www.wolframalpha.com/input/?i=limit+n%5E%282%2Fn%29+pi%2F4%2C+n+to+inf
it helps to actually take the root test
and the next one, i dont htink factorials are well suited to root tests
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