Sin40+sin60= sin20-sin40= cos15+cos45= cos46-cos74=

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