All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers > Sequences
Find Formula (Posted on 2012-02-17) Difficulty: 3 of 5
Derive a formula for the product of the first n members of an arithmetic progression with an initial element a and a common difference d;(a*d>0).
Verify the validity of your expression for (a,d,n)=(2,3,8).

See The Solution Submitted by Ady TZIDON    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Find Formula Solution | Comment 2 of 4 |

 

    Definition :

  ð(1...q)[F(k) ]  = multiplications of F(k) from k=1 to k=q .

  

      F(k)=(a^2+a*n*d-a*d-n*d^2)+[(n+1)*d^2*k-d^2*k^2] 

    for even n the solution is :

   ð(1...n/2)[F(k)]

      for odd n, the solution is :

   (a+0.5*d*(n-1) )*ð (1...(n-1)/2 )F(k)

  

  

  

 

 

   


  Posted by Dan Rosen on 2012-02-19 09:29:55
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (14)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information