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╔(σ_σ)╝
#6
Dec26-09, 06:15 PM
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P: 849
Quote Quote by tiny-tim View Post
No, √(1 - cos(θ - φ))/2 is correct.


How did you reformulate P and Q for that?
But I can't seem to find a simple manipulation for P and Q to get the second formula all I can find is

(P dot e1)(Q dot e1) - (P dot e2)(Q dot e2)

Where e1 = (1,0) and e2 = (0,1)

Again the back of my book gives the expanded for of cos([tex]\phi[/tex] + [tex]\theta[/tex]) so I don't even know what they are trying to say.
As I said previously.

Is there an easier way ?