If `veca +vecb +vecc =vec0, |veca| = 3 |vecb| =5` and `|vecc|=7` then show that angle between `veca` and `vecb` is `60^(@)`

What is the angle between vectors veca and vecb ?

If veca and vecb be two vectors such that | veca| = sqrt(3) | vecb | =2 and veca. vecb = sqrt(6) what is the angle between veca and vecb ?

If |veca + vecb | =|veca - vecb | then show that veca and vecb are perpendicular .

If |veca | = 2 , | vecb | = sqrt(11) and veca xx vecb = 2hati + 2hatj + 6 hatk then what is the angle between veca and vecb ?

Two vectors vecA and vecB are such that vecA + vecB = vecC and A + B = C Write down the relation between vecA and vecB in each case.