My Math Forum  

Go Back   My Math Forum > College Math Forum > Applied Math

Applied Math Applied Math Forum


Reply
 
LinkBack Thread Tools Display Modes
June 1st, 2008, 04:12 PM   #1
Newbie
 
Joined: Jun 2008

Posts: 3
Thanks: 0

"Recursive definition"

Can anyone give "recursive" definition of the sequences given below?
n = 1,2,3...

Code:
a) a_n = 4n-2
b) a_n = 1 + (-1)^n
c) a_n = n(n+1)
d) a_n = n^2
Thanks for any quick help!
Please provide me with explanation too!

Also, is there any LaTeX in this forum?
robocop_911 is offline  
 
June 1st, 2008, 05:40 PM   #2
Global Moderator
 
CRGreathouse's Avatar
 
Joined: Nov 2006
From: UTC -5

Posts: 16,046
Thanks: 938

Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms
If you write out a_n - a_(n-1), you'll find the recursive forms fairly easily. For the first, a_n - a_(n-1) = (4n - 2) - (4(n-1) - 2) = 4, so a_n = a_(n-1) + 4.

LaTeX is coming soon!
CRGreathouse is offline  
June 1st, 2008, 06:15 PM   #3
Newbie
 
Joined: Jun 2008

Posts: 3
Thanks: 0

Quote:
Originally Posted by CRGreathouse
If you write out a_n - a_(n-1), you'll find the recursive forms fairly easily. For the first, a_n - a_(n-1) = (4n - 2) - (4(n-1) - 2) = 4, so a_n = a_(n-1) + 4.
LaTeX is coming soon!
Code:
Is this true for 2nd one...

a_n - a_n-1 = 2 (-1)^n 

Is this recursive definition correct? for question b)
robocop_911 is offline  
June 1st, 2008, 10:43 PM   #4
Global Moderator
 
CRGreathouse's Avatar
 
Joined: Nov 2006
From: UTC -5

Posts: 16,046
Thanks: 938

Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms
No. (-1)^n - (-1)^(n-1) is either 2 or -2. a_n + a_(n-1) = 0.
CRGreathouse is offline  
Reply

  My Math Forum > College Math Forum > Applied Math

Tags
recursive definition



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Statistics "Independent " definition calebh Probability and Statistics 1 January 26th, 2013 03:41 PM
A "simple" application of dirac delta "shift theorem"...help SedaKhold Calculus 0 February 13th, 2012 12:45 PM
"separate and integrate" or "Orangutang method" The Chaz Calculus 1 August 5th, 2011 10:03 PM
What does "definition" mean in mathematics? Amir Kiani Algebra 2 March 19th, 2009 02:02 PM
sample exeriment-need help finding "statistic" and "result" katie0127 Advanced Statistics 0 December 3rd, 2008 02:54 PM





Copyright © 2018 My Math Forum. All rights reserved.