And (C) if vector 1121130 - 31 + b) Prove that if perpendicular 3a + 3b = 0.

If a,b are unit vectors such that the vector a + 3b is perpendicular to 7a - 5b then the angle between a and b is

Three vector A,B and C satisfy the relation A.B=0 and A. C =0. Then the vector A is perpendicular to

The vector p=(a*c)b-(a*b)c is be perpendicular to

vec a , vec b and vec c are the position vectors of points A ,B and C respectively, prove that : vec a× vec b+ vec b× vec c+ vec c× vec a is vector perpendicular to the plane of triangle A B Cdot

The vectors 3a5b and 2a+b are mutually perpendicular and the vectors a+4b&-a+b are also mutually perpendicular.Then the acute angle between a and b is