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SAMIA
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Hello I hope you can help me in solving this proof
proved A x [B x (Cx D) ] = 0
Thank you
proved A x [B x (Cx D) ] = 0
Thank you
Hello Samia, welcome to PF. Since this is your first post you may not have read the rules, one of which is you must show what you have tried. Nevertheless I will give you a Hint: Try the calculation with 4 different vectors.
that's just...cruel.
presumably A,B,C and D lie in R^{3}?
if so, A must be a linear combination of B,C, and D.
the cross-product is distributive, is it not?
from here it get easy....because of a certain elementary property of cross-products.
How does it get easy when it is false? And what is cruel about suggesting that most anything will give a counterexample?