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Chadlee88
Mar29-07, 03:54 AM
1. The problem statement, all variables and given/known data

I have been workin on a mathematical induction question and have run into trouble with the simplification.



2. Relevant equations



3. The attempt at a solution

I know that the solution i am trying to reach is (k+2)!-1
but i do not know where to go from the equation:
(k+1)!-1 + (k+1)(k+1)! could someone plz help.

jing
Mar29-07, 04:45 AM
(k+1)!-1 + (k+1)(k+1)! could someone plz help.

rearrange - put the -1 at the end and then look closely at the two terms now together.

If you require more help please show what you have tried.

mjsd
Mar29-07, 05:38 AM
if in doubt always write out what the factorial really means

VietDao29
Mar29-07, 07:06 AM
Try to factor out (k + 1)!, and see if you can get the answer. Note that:
(n + 1) n! = (n + 1)!
Can you go from here? :)

sutupidmath
Mar29-07, 09:09 AM
(k+1)!-1 + (k+1)(k+1)!= (k+1)!+(k+1)(k+1)!-1, so here as the
others explained you need to factor out (k+1)!, so you will get
(k+1)!(1+k+1)-1=(k+2)(k+1)!-1, so now look at what vietdao said, and you will come to the right answer.