cos105cos5 + sin105cos85 cos105cos5 + sin105cos(90-5)
--------------------------------------------= --------------------------------------------------------------=
sin195cos5 + cos195sin185 sin(105+90)cos5 + cos(105+90)(sin180+5)
cos105cos5 + sin105sin5
= -------------------------------------------- =1
cos105cos5 + (-sin105)(-sin5)
2)sin75cos5 - cos75cos85 sin(90-15)cos5 - cos(90-15)cos(90-5)
--------------------------------------- = -------------------------------------------------------- =
cos375cos5 - sin15sin365 cos(360+15)cos5 - sin15sin(360+5)
cos15cos5 - sin15sin5
= ----------------------------------- =1
cos15cos5 - sin15sin5