Suppose `veca` and `vecb` are vectors such that a x b =(1,0,2). What is `vecb` x [-2a]?

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Using the properties of the cross product, `vec(u)Xvec(v)=-vec(v)Xvec(u)` and `(avec(u))Xvec(v)=a(vec(u)Xvec(v))`

 

 

`vecb X (-2vec a)=-(-2veca)X vecb``=-(-2)` `(vecaXvecb)=2(vecaXvecb)=2(1,0,2)`

Answer: `vecb X(-2vec a)=(2,0,4)`

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