`l veca . m vecb = lm(veca . vecb)` and `veca . vecb = 0` then `veca` and `vecb` are perpendicular if `veca` and `vecb` are not null vector

If |veca+vecb|=|veca-vecb|, (veca,vecb!=vec0) show that the vectors veca and vecb are perpendicular to each other.

If veca, vecb, vecc are vectors such that veca.vecb=0 and veca + vecb = vecc then:

If |veca+vecb|=|veca-vecb| show that veca_|_vecb .

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 vecA+vecB=vecR and 2vecA+vecB is perpendicular to vecB then

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 two vectors such that | (veca+vecb)=|veca| then prove that 2 veca + vecb is perpendicular to vecb.