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# a Vector Cross Product (Pure 4) Question watch

1. The exam's tomorrow and I've just come across a vector question that I can't figure out.

"v and w are non-parallel vectors.

"Show that (v + 2w) X (v - 3w) = k(v X w), where the real number k is to be found."

I expanded it (the distributive property of vector product over vector addition) but have no idea how to simplify it to how the question wants it.

The rest of the vectors topic I have no trouble with, its just this... Would greatly appreciate any help.

Cheers
2. (V +2W)x(V-3W)
=VxV-3VxW+2WxV-6WxW

for vectors a and b:
a x a=0

axb=-bxa

change WxV into -VxW

MEI paper?

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Updated: June 8, 2004
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