# Perpendicular vectors

• May 30th 2010, 11:10 AM
kandyfloss
Perpendicular vectors
I've have another question

how do you find a vector which is perpendicular to both 3i-6j-4k and -3i+2j+2k
• May 30th 2010, 11:19 AM
Plato
Quote:

Originally Posted by kandyfloss
how do you find a vector which is perpendicular to both 3i-6j-4k and -3i+2j+2k

Find the cross-product: $<3,-6,-4>\times<-3,2,2>$.
• May 30th 2010, 11:24 AM
kandyfloss
i need to find without using the cross product,since we haven't learnt that yet