sin40+sin60=
sin20-sin40=
cos15+cos45=
cos46-cos74=

sin(40°)+sin(60°)(2*sin(2*пи/9)+корень(3))/2=1.6cos(15°)+cos(45°)(корень(2)*cos(пи/12)+1)/корень(2)=1.67cos(46°)-cos(74°)cos(23*пи/90)-cos(37*пи/90)=0.42