Sin2(ankyan astichan@)+cos2(ankyan

astichan@)=1

Ctg2(ankyan astichan@)=cos(ankyan

astichan@)/sin(ankyan astichan@)

Tg(ankyan astichan@)=sin(ankyan

astichan@)/cos(ankyan astichan@)

tg(ankyan astichan@)*ctg(ankyan astichan@)=1