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!

Integrating with unknown method

  1. Dec 14, 2011 #1
    1. The problem statement, all variables and given/known data

    If (the integral from -3 to 2)f(x)dx=-1, (the integral from -1 to 5)f(x)dx=8, and (the integral from -3 to 5) f(x)dx=6, then (the integral from -1 to 2)f(x)dx= ?

    2. Relevant equations

    This is the part I'm struggling with.

    3. The attempt at a solution
    I know that the answer is as follows:

    Note that (the integral from -3 to -1) f(x)dx= (the integral from -3 to 5)f(x)dx- (the integral from -1 to 5) f(x)dx= 6-8= -2. So (the integral from -1 to 2) f(x)dx= (the integral from -3 to 2) f(x)dx- (the integral from -3 to -1) f(x)dx= -1-(-2)= 1

    I just don't understand what rule allows you to do the above.
  2. jcsd
  3. Dec 14, 2011 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    How does the integral from -3 to -1 plus the integral from -1 to 2 plus the integral from 2 to 5 , compare to the integral from -3 to 5 ?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Integrating with unknown method
  1. Integration methods (Replies: 1)

  2. Method of integration? (Replies: 3)