Solving for F1 Angle Components using Spherical Coordinates

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Homework Statement


Diagram of a force vector F1 = 80 lb pointing left from the origin, with a 30° angle to the horizontal and a 40° angle in the x-y plane, plus a vertical force F2 = 130 lb pointing down along the negative z-axis.


Specify the coordinate direction angle α,β,γ of F1.

Homework Equations





The Attempt at a Solution



γ= 90-30 = 60
The only obvious one.

I have no clue how I'm supposed to see what the other are. α seems to me like it's 320 degrees because if you rotate in the positive direction on the XY-plane then that's where you'll end up.

To find the final angle I suppose I'm just supposed to use the equation with the cosine of all three angles squared.
 
You need to start by clearly stating the definitions of the angles.
 
Hint 1: The components of a unit vector in a direction give the direction cosines.

Hint 2: How are your given angles related to spherical coordinate angles?