Engineering formula
Projection of a Force onto an Axis
$$Fₓ = F cos α$$
The projection of a force $F$ onto the $x$ axis is determined from the angle $\alpha$ between the force vector and the positive direction of the axis:
$$F_x=F\cos\alpha$$
The sign of the projection is automatically accounted for by the cosine when the directed angle is used. If only an acute reference angle is given, determine the sign from the actual force direction.