1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Trouble Writing Sum

  1. Nov 23, 2013 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data

    I'm having trouble writing a sum for this:


    2. Relevant equations

    delta x = (b-a)/n

    n = 4
    b-a = 2
    delta x = 1/2

    3. The attempt at a solution

    I keep writing this. But we can't solve this for anything; 4/i when i = 0 is infinity. What am I doing wrong?

  2. jcsd
  3. Nov 23, 2013 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    For one thing, f(x) = 2/x. IDK what 4/i is supposed to represent.
  4. Nov 23, 2013 #3


    User Avatar
    Gold Member

    I think the issue here is finding the correct general term for xi and the correct bounds of summation.

    I did it again, and this time for the general term I am using i/2 + 1, and the bounds of summation as i = 0 and i = 3.

    I find that drawing a sketch helps. Immensely.

    Last edited: Nov 23, 2013
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted