Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Math Topics » discretemath

Topic: induction question
Replies: 9   Last Post: Feb 27, 2007 11:04 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ] Topics: [ Previous | Next ]
Narcoleptic Insomniac

Posts: 797
From: Racine, WI
Registered: 3/10/05
Re: induction question
Posted: Feb 27, 2007 9:50 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On Feb 27, 2007 1:44 AM CT, Earth wrote:

> 1+2+3+...+n =n(n+1)/2
> conclusion
> (n-1)n/2+n = n(n+1)/2


For this one you're asked to prove that

1 + 2 + ... + n = n(n + 1) / 2

...via induction. This is a formula - it gives us the
value of the summation of the first n integers as a
product.

It seems you know how to do this. First, you show that
the formula is true for the first few n (n = 1, 2, etc).

Then you assume that it is true for n = k (our induction
hypothesis), and proceed to show that it is true for n =
k + 1.

> a)what would be the last step in a similar inductive
> proof that
> n(1/1! + 1/2! +...+(-1)^n/n!)?
> what is the conclusion on this? how do work on it to
> get answer?


This, on the other hand, is not a formula nor an
equation for anything.

It is an expression - you cannot prove an expression.

Regards,
Kyle Czarnecki



Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2013. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.