for n:=1 to 50 do :
1
2
2.15470053837925
2.41421356237309
2.70130161670408
3
3.30476487096249
3.61312592975275
3.92380440016309
4.23606797749979
4.54946553288422
4.86370330515627
5.17858146886038
5.49395920743493
5.80973434474413
6.12583089548301
6.44219115175181
6.75877048314363
7.07553382097426
7.39245322149966
7.7095061398084
8.02667418333227
8.34394219610391
8.66129757554039
8.97872975555948
9.29622981055875
9.61379014847791
9.93140427038051
10.2490665803026
10.5667722335056
10.8845170143696
11.2022972373783
11.520109666252
11.8379514474594
12.155820055209
12.4737132456699
12.7916290186635
13.109565585441
13.4275213414455
13.7454948431824
14.0634847884921
14.3814899996548
14.6995094088628
15.0175420456841
15.3355870262037
15.6536435435869
15.9717108598527
16.2897882986785
16.6078752390897
16.9259711099087

pi = 3.14159265;
alf = (n - 2) * 180 / (2 * n);
ans = 1. + 1. / cos((alf * pi) / 180);
cout << ans;