Cos107*cos17+sin107*sin17= cos36*cos24-sin36*sin24= sin63*cos27+cos63*sin27= sin51*cos21-cos51*sin21= 

Формулы (синус и косинус суммы и разности): [latex]sin(a+b) =sina*cosb+cosa*sinb[/latex]  [latex]sin(a-b) =sina*cosb-cosa*sinb[/latex]  [latex]cos(a+b) = cosa*cosb-sina*sinb[/latex]  [latex]cos(a-b) = cosa*cosb+sina*sinb[/latex]  1) cos107*cos17+sin107*sin17= cos(107-17) = cos90 = 0 2)  cos36*cos24-sin36*sin24= cos(36+24) = cos60 = 1/2 3)  sin63*cos27+cos63*sin27= sin(63+27) = sin90 = 1 4)  sin51*cos21-cos51*sin21=  sin(51-21) = sin30 - 1/2