а) sin 26 + sin 14 = 2sin((26+14)/2)cos((26-14)/2)= 2sin 20cos 6
б) cos 18 - cos 10 = -2sin((18+10)/2)sin((18-10)/2)= -2sin 14sin 4
а) sin 26 + sin 14 = 2sin((26+14)/2)cos((26-14)/2)
= 2sin 20cos 6
б) cos 18 - cos 10 = -2sin((18+10)/2)sin((18-10)/2)
= -2sin 14sin 4