Solving for Spherical Coordinate Angles in 3D: Understanding the Formulas

[ricky_fusion]

Hi guys,
This is my first time in this forum, thanks for your time.
Now, I learn about spherical angles (vektor) in 3 Dimension
I still confuse about the formula, such as:
Fx = F sinφ cosθ ( in X axis = i)
Fy = F sinφ sinθ ( in y-axis = j)
Fz = F cosφ ( in z axis = k)

I want to send the pictures too, but I still don't have the way to upload it.Maybe next time.
Does anybody know about why in X axis there are sin and cos but in Z axis there is only cos??
Thaks for your help.

 

[zoner7]

You can calculate all these by playing around with right triangles... I only just learned this stuff 2 weeks ago, so I can hardly explain it in words. I would look around online for a detailed picture that explains how the equations are geometrically derived. it isn't too complicated.

 

[jtbell]

Does this diagram help?

 

[ricky_fusion]

Hmm..
Yes, you are right, Thanks a lot.