If and are two unit vectors such that + is also a unit vector, then find the angle between and
Write the number of vectors of unit length perpendicular to both the vector and
If A = {1, 2, 3}, B = {4, 5, 6, 7} and f = {(1, 4), (2, 5),(3, 6)} is a function from A to B. State whether f is one-one or not.