(adsbygoogle = window.adsbygoogle || []).push({}); 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) - ∇^{2}A 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.)

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# How to prove vector identities WITHOUT using levi civita ?

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