Question

If two non zero vectors a bar and b bar obey the relation a bar+b bar= ‐ b bar the angle between them is

Answer 1

A.B=A×B      here A and B means A and B vector

A B cosФ=A B sinФ

sinФ/cosФ=1

tanФ=1

tanФ=tanπ/4

Ф=π/4