You are Here: Home

# a Vector Cross Product (Pure 4) Question watch

Announcements
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?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 8, 2004
Today on TSR

### Edexcel GCSE Maths Unofficial Markscheme

Find out how you've done here

### OCR AS Chemistry Exam Discussion

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE