Results 1 to 3 of 3

Math Help - Practice Problem (Intro to Discrete Math Class)

  1. #1
    Junior Member
    Joined
    Aug 2007
    Posts
    32

    Practice Problem (Intro to Discrete Math Class)

    Hey Everyone,

    Just so you know I am in an Intro to Discrete Math class so this stuff should be pretty simple to the rest of you, but I'm not very good at it. This is an example question that is up to me if i want to do it or not, the professor does not care. Any help would be appreciated.

    Given that A_n=5n+3 for any n>=1, is it true that A_n=5*A_{(n-1)} -3?
    Last edited by Edbaseball17; January 15th 2009 at 09:42 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,367
    Thanks
    1312
    Quote Originally Posted by Edbaseball17 View Post
    Hey Everyone,

    Just so you know I am in an Intro to Discrete Math class so this stuff should be pretty simple to the rest of you, but I'm not very good at it. This is an example question that is up to me if i want to do it or not, the professor does not care. Any help would be appreciated.

    Given that A_n=5n+3 for any n>=1, is it true that A_n=5*A_(n-1) -3?

    I'm new to this so not sure how to make (n-1) all subscript, but it should be.
    To make all of some expression a subscript enclose it in { }.
    To calculate that, think of A_n as a function A(n).
    If A_n= 5n+3, then A_{n-1}= 5(n-1)+ 3= 5n- 2.
    Put 5n+3 in place of A_n and 5n- 2 in place of A_{n-1} in that expression and see if it is true.
    Is 5n+3= 5(5n-2)-3?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Aug 2007
    Posts
    32
    Quote Originally Posted by HallsofIvy View Post
    To make all of some expression a subscript enclose it in { }.
    To calculate that, think of A_n as a function A(n).
    If A_n= 5n+3, then A_{n-1}= 5(n-1)+ 3= 5n- 2.
    Put 5n+3 in place of A_n and 5n- 2 in place of A_{n-1} in that expression and see if it is true.
    Is 5n+3= 5(5n-2)-3?

    ok so here is what I cam up with:

    5n+3 = 5(n-2)-3 = 25n-10-3 = 25n-7

    so the answer is false.

    is this correct?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Math problem but from Chemistry class..
    Posted in the Algebra Forum
    Replies: 3
    Last Post: September 20th 2010, 10:43 PM
  2. Discrete Math - Last Problem. Need Help!
    Posted in the Discrete Math Forum
    Replies: 6
    Last Post: January 31st 2009, 10:03 AM
  3. Replies: 4
    Last Post: November 16th 2008, 01:40 PM
  4. An algorithm problem Discrete Mathematics class
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: August 26th 2008, 04:34 PM
  5. Help with Intro to Abstract Math Class...
    Posted in the Advanced Algebra Forum
    Replies: 6
    Last Post: March 20th 2006, 02:52 PM

Search Tags


/mathhelpforum @mathhelpforum