If ` vecA + vecB ` is perpendicular to `vecA - vecB ` , then find the angle `theta` between A and B

The resultant of vecA and vecB is perpendicular to vecA . What is the angle between vecA and vecB ?

If (veca + 3 vecb) is perpendicular to ( 7 veca - 5 vecb) and ( veca - 4 vecb) is perpendicular to ( 7 veca - 2 vecb) , then the angle between veca and vecb ( in degrees ) is ______

If veca , vecb are unit vectors such that the vector veca + 3vecb is peependicular to 7 veca - vecb and veca -4vecb is prependicular to 7 veca -2vecb then the angle between veca and vecb is

If sqrt3|vecAxx vecB|= vecA*vecB , then find the angle between vecA and vecB .

Two vectors vecA" and "vecB have equal magnitudes. If magnitude of vecA+vecB is equal to n times the magnitude of vecA-vecB , then the angle between vecA" and "vecB is :-

If veca and vecb are two unit vectors such that veca+2vecb and 5veca-4vecb are perpendicular to each other, then the angle between veca and vecb is

If |vecA + vecB| = |vecA - vecB| , then the angle between vecA and vecB will be

If veca, vecb,vecc are unit vectors such that veca is perpendicular to the plane of vecb, vecc and the angle between vecb,vecc is pi/3 , then |veca+vecb+vecc|=

If vecA.vecB = |vecA xx vecB| , find angle between vecA and vecB .