sin20cos10 + cos20sin10 = sin(20+10)cos50cos5 + sin50sin5 = cos(50+5)sin71cos11 - cos71sin11 = sin(71-11)cos25cos65 - sin25sin65 = cos(25-65)
sin (a+b) - sin(a-b) =
sinAcosB+cosAsinB - sinAcosB - cosAsinBsin (a+b) - sin (a-b) sinAcosB+cosAsinB - sinAcosB - cosAsinBДальше сама по формулам там похожеcos(a+b)=cosA+cosB-sinA+sinBcos(a-B)=cosAcosB+sinAsinBsin(a+b)=sinAcosB+cosAsinBsin(a-b)=sinAcosB-cosAsinB