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## Homework Statement

Hi everybody, I am trying to do a numerical aplication of change of coordinate system to another; the objective is to calculate the azimut of the sun knowing the altitude, hour angle and declination .

## Homework Equations

Cosh * Sina = Cosδ * Sin H

where a is the azimut

h is the altitude, in this case 27.5°

δ is the declination, in this case 7.2°

and H is the hour angle, in this case 10:00 on GTM+2; so 20h which is 300°

## The Attempt at a Solution

Sina = [ Cosδ * Sin H ] / CosH

If I substitute the values, the azimut is -75.6°.

The problem is that if I check the value of the azimut on the program stellarium for august 12 2014, the date from where the data has been chosen, the azimut is of 104º, and I don't know why there is such a difference between my azimut and the program's, Can anyone help please?