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!

How to prove vector identities WITHOUT using levi civita ?

  1. Nov 27, 2017 #1
    Mentor note: Thread moved from homework sections as being a better fit in the math technical section.
    Multiplying components of both sides are also off limits.
    I am trying to derive vector identities on introduction chapters in various EMT books. For example : (AXB).(CXD) = (A.C)(B.D) - (A.D)(B.C)
    After a few hours i noticed B.(CXD) = C.(DXB) and replaced B's with AXB's its Done.
    AX(BX(CXD)) was even simpler didnt take any time at all.
    I want to do that to
    ∇. (AXB) = B.(∇xA) - A.(∇xB)
    ∇x(AxB) = ....
    ∇(A.B) = ...
    ∇x(∇xA) = ∇(∇.A) - ∇2A etc

    So far last 2 days after solving the first two of them just looking them and hoping to see it. What i should do to improve my ability to see them fast ? (I also have to finish half the book in 2-3 weeks before exam so i am hoping to solve this problem in a few days at most.)
     
    Last edited by a moderator: Nov 27, 2017
  2. jcsd
  3. Nov 27, 2017 #2

    jedishrfu

    Staff: Mentor

  4. Nov 27, 2017 #3
    Thank you. It wasnt what i wanted at all but some way i didnt imagine they were still helpfull. Instead of working on my weakness i will go on with my strengths.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: How to prove vector identities WITHOUT using levi civita ?
Loading...