1
sin(90-3)-sin59-sin(90+3)+sin61=cos3-sin59-cos3+sin61=sin61-sin59=
=2sin[(61-59)/2]cos[(61+59)/2]=2sin1*cos60=2*1/2*sin1=sin1
sin1=sin1
2
cos(180-65)-cos35+cos65+cos25=-cos65-cos35+cos65+cos25=
=cos25-cos35=-2sin[(25-35)/2]*sin[(25+35)/2]=-2sin(-5)*sin30=
=2*1/2*sin5=sin5
sin5=sin5