Thanks for replies, however I am still confused , especially the signs (quadrants).
The Equation I showed earlier is in reality like this:
TAN(P) = COS (A) / - [ SIN (A)*COS(E) + TAN(L)*SIN(E)]
P : Can have any value between 0 to 360 Degrees
E : Typical value is around 23 Degrees.
L : Can assume values between -90 Degrees to +90 Degrees
A : Can have value between 0 - 360 degrees
I have sample data (all in Degrees):
P = 281.1531
L = 16.8666
A = 199.9208
(Value of A is to be found , when P,E,L are given)
Now as per the suggestions received ,
As a first step I replaced COS A by SQRT (1 - SIN2 A)
COS A = COS (199.9208) = -0.94016
SQRT (1 - SIN A2) = SQRT( 1 -0.116091) = SQRT(0.8839)=0.94016
So there is sign change for COS(A) :: SQRT(1-SIN(A)2)
Similar confusion is with TAN Square required at a later step.
Because of this Sign changes (perhaps the Quadrant changes) Ia m finding it difficult to make this a generalized , to convert it into a computer program.
Can anybody explain this , any workaround, anything is missing,?