sin105°=
cos105°=
tg105°=
ctg105°=

sin 105 = sin( 90 + 15 ) = cos 15cos ( 90 + α ) = - sin αcos 105 = cos( 90 + 15 ) = -sin 15tg ( 90 + α ) = -ctg αtg 105 = tg( 90 + 15 ) = -ctg 15