N :
/
E :
f(α) = (1+cos(nα))
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0°
15°
30°
45°
60°
75°
90°
105°
120°
135°
150°
165°
180°
195°
210°
225°
240°
255°
270°
285°
300°
315°
330°
345°