# need to derive a formula

• Sep 1st 2010, 05:39 AM
grgrsanjay
need to derive a formula
need a formula for this expression
$\frac{1^5 + 2^5 + 3^5 + ..... +(n-1)^5 + n^5}{1^4 + 2^4 + 3^4 + ..... + (n-1)^4 + n^4}$
• Sep 1st 2010, 05:47 AM
Ackbeet
See here.
• Sep 1st 2010, 06:05 AM
grgrsanjay
$\frac{(2n^6 + 6n^5 +5n^4 - n^2)30}{(6n^5 + 15n^4 +10n^3 - n)12}$

i need derivation for this expression
• Sep 1st 2010, 06:09 AM
Ackbeet
Right. Well, I would probably prove the numerator and denominator sums separately, using induction. Then you'd pretty much be done.
• Sep 1st 2010, 06:15 AM
grgrsanjay
Quote:

Originally Posted by Ackbeet
Right. Well, I would probably prove the numerator and denominator sums separately, using induction. Then you'd pretty much be done.

Quote:

Originally Posted by grgrsanjay
well,that would be okay.

okay
• Sep 1st 2010, 06:42 AM
Soroban
Hello, grgrsanjay!

What course are you taking?

These derivations are not difficult ,
. . but if we are limited to basic Algebra,
. . they will take pages and pages!

• Sep 1st 2010, 05:13 PM
grgrsanjay
oh OK anyway i got the answer
thank you guys :(
• Sep 1st 2010, 05:20 PM
Ackbeet
Not exactly sure why you're frowning. If you got the answer on your own, that's the best result! That means you own the answer, and you'll understand the problem a lot better than if I were to simply show you the answer.