Let us compute the vector product V = P × Q, where the vector P is of magnitude 6 and lies in the zx plane at an angle of 30° with the x axis, and where the vector Q is of magnitude 4 and lies along the x axis (Fig. 3.7).
It follows immediately from the definition of the vector product that the vector V must lie along the y axis, directed upward, with the magnitude
V = PQ sin θ = (6)(4) sin 30° = 12 ■