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#2 Help Me ! » Find the Radius of convergence for the following power series.... » 2008-05-29 11:17:51

adam_dsutton
Replies: 7

I am having trouble finding the radius of convergence for:

I am not sure how to deal with the n!

All help is much appreciated! smile

P.s the sum is from n=0 to infinity...i didnt know how to do this using code

#3 Re: Help Me ! » Inequality Help Please » 2007-10-07 10:42:24

Okay, that makes things alot clearer, thankyou both.

#4 Re: Help Me ! » Inequality Help Please » 2007-10-07 05:05:15

Thanks Jane, but if say lx-1l<0, why must it be equal to -x+1???
Also how do you determine the considered regions, I can understand graphically but not algebraically.
smile

#5 Help Me ! » Inequality Help Please » 2007-10-07 04:05:44

adam_dsutton
Replies: 4

Solve the following inequality:

lx-1l+lx-2l ≥5

I am struggling how to work this out, I tried case analysis but I don't think i'm doing it correctly, all help is appreciated.
Also how do you write the modulus lines using latex?

Thanks, Adam:)

#6 Re: Help Me ! » Number Theory » 2007-09-20 11:52:36

All primes are odd apart from 2, so p+1 either equals 2+1=3 or an (odd number +1)=even number "n^3".
As 3 is not a cubed integer we know that p≠2.  This means "n^3" is even, thus meaning "n" must be even as (even)^3=even and (odd)^3=odd, and as 2 is the only even prime number, n=2
therefore, p+1=2^3=8
Meaning p=7
smile

#9 Re: Exercises » Cryptarithms » 2007-09-20 02:32:51

I agree with Identity, if t=9 then:
The first "f" in effort =9+I+1 ...the "1" being carried over.
The second "f" in effort =9+A+1...the "1" being carried over.

Which implies I=A, making it contradictory. :S

#10 Re: Puzzles and Games » Spot the error » 2007-09-14 03:14:31

what do you mean by "i"???...imaginary number? :S

#12 Re: Help Me ! » Log differentitation » 2007-09-13 04:52:30

I understand everything apart from the first line...how do you know that f'(x)=1/(xlna) if f(x)=loga(x) ???
also the answers tell me that the answer is 1+(1/x) :S

thanks though luca, I hate to be a bother

#13 Re: Help Me ! » Log differentitation » 2007-09-13 04:21:13

Okay, i've completed 2a) by substituting (ln) instead of log base 10, but I still can't get the correct answers for the other two questions.

#14 Re: Help Me ! » Log differentitation » 2007-09-13 03:36:48

well i'm presuming log with base 10 but i dont actually know for sure, i just copied the questions exactly :S

#15 Help Me ! » Log differentitation » 2007-09-13 03:24:34

adam_dsutton
Replies: 10

Hi, I'm struggling with the following questions.

1. Differentiate the following with respect to x:     y=log(xe^x)

2. Find the derivatives of the following functions at the indicated points:

a) (cosx).log(3x)  , x=pi

b) log((x^3)/(x^0.5))  ,  x=5/2

Any help is much appreciated as I havent a clue what to do here.
Thanks, Adam

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