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# A discrepency in p6 question? watch

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1. Okay; look at Q2 on this here paper:

http://www.aqa.org.uk/qual/gceasa/qp...W-QP-Jan02.pdf

And work it out, first using the vectors A to B and B to C

You should get d = 6 and n= vector (1 2 3)

this is correct.

Now try with A to B and A to C

I don't know if I've got it wrong, with the signs int he cross product bit, but does this not give n = (-1 -2 3) and d =0???
2. (Original post by Mat666)
Okay; look at Q2 on this here paper:

http://www.aqa.org.uk/qual/gceasa/qp...W-QP-Jan02.pdf

And work it out, first using the vectors A to B and B to C

You should get d = 6 and n= vector (1 2 3)

this is correct.

Now try with A to B and A to C

I don't know if I've got it wrong, with the signs int he cross product bit, but does this not give n = (-1 -2 3) and d =0???
Youve done it wrong ABxAC = i + 2j + 3k
3. AB = (-3 3 -1) AC = (-2 1 0)

A x B = (1 2 3)
4. cheers, just checking...

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