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!

Question about a notation.

  1. Apr 21, 2010 #1
    Hey Everyone,

    This may be a silly question and I am able to interpret the intention of the notation but I am just curious exactly what it is.

    I am attaching an image of the page out of my text book and it is near the bottom. C = C1 U C2.

    Sorry again if this is a silly question, I just wanted to make sure I understand this notation outside the context of this problem. I am sure I have seen it before but I am still not sure.

    Thanks,
    Rob
     

    Attached Files:

  2. jcsd
  3. Apr 21, 2010 #2

    Mark44

    Staff: Mentor

    Your attachment hasn't been approved yet.

    Are you asking about C1 U C2? The U symbol is "union".

    x is an element of A U B if x is an element of A or x is an element of B. The "or" really means "and/or" to include elements that might be in both sets.

    For example, if A = {1, 2, 3, 5, 8} and B = {3, 6, 9, 12}, then A U B = {1, 2, 3, 5, 6, 8, 9, 12}.

    Another set operation is "intersection" [itex]\bigcap[/itex]. x is an element of A [itex]\bigcap[/itex] B if x is an element of A and x is an element of B. Using the same example, A [itex]\bigcap[/itex] B = {3}.
     
  4. Apr 22, 2010 #3

    HallsofIvy

    User Avatar
    Science Advisor

    In this case [itex]C_1[/itex] is the straight line from (0, 2) to (3, 2) and [itex]C_2[/itex] is the straight line from (3,2) to (3,5). "[itex]C= C_1\cup C_2[/itex]" is the two paths put together: to integrate along C, integrate along [itex]C_1[/itex] and [itex]C_2[/itex] and add the two integrals.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook