This velocity vector could then be pointing up and to the right or up and to the left. Since we only want the magnitude of the x-axis velocity, it doesn't matter. In any case if there is a 60° angle from the y-axis means the sin of the angle gives the x-component. (Typically the angle is given with respect to the x-axis in which the sin gives the y-component)
For this case
[tex]v_x=4sin(60)\frac{m}{s}=3.464 \frac{m}{s} [/tex]
