Find the unit vector perpendicular to botha ? andb ? when: a ?=2i ?+j ?-2k ?andb ?=3i ?-j ?+k ?

Asked by Manoj | 9th May, 2013, 08:50: PM

Expert Answer:

To find a vector perpendicular to the given 2 vectors, we can simply find the cross product of the same. 
 
a =2i+j-2k andb =3i-j+k
 
Hence, a xb = (2i+j-2k) x (3i-j+k)
= -2k -2j -3k+i -6j -2i
= -i-8j-5k
 
Hence, unit vector would be = (a xb)/|(axb)|
= -i-8j-5k /(sqrt(1+64+25))
 = -i-8j-5k/3sqrt(10)

Answered by  | 10th May, 2013, 05:03: AM

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