What is the projection p of b 1 2 2 onto a 2 2 1Solutionpro

What is the projection p of b = (1, 2, 2) onto a (2, -2, 1)?

Solution

projection of b on a would be mod of b times cosine of angle between a and b vector.

To find the cosine of anfle between a and b , we find the dot product of a and b.

a.b = 2-4+2=0

Which means the angle between them is 90 degrees , cos 90 = 0.

Thus the projection is 0.