Divkārša argumenta trigonometrisko funkciju formulas
sin2a = 2sina cosa cos2a = cos2a – sin2a = 2cos2a – 1 = 1 – 2sin2a
tg2a = 2tga/1-tg2a ctg2a = ctg2a – 1/ 2ctga
Formulas funkciju summas pārveidošanai reizinājumā
sina + sinb =2(sin (a+b/2)) (cos (a-b/2))
sina - sinb =2(sin (a-b/2)) (cos (a+b/2))
cosa + cosb =2(cos(a+b/2)) (cos (a-b/2))
cosa - cosb = - 2(sin(a+b/2)) (sin (a-b/2))
Formulas funkciju reizinājuma pārveidošanai summā
sina cosb = 0,5(sin(a-b)+sin(a+b))
sina sinb =0,5(cos(a-b) – cos(a+b))
cosa cosb =0,5(cos(a-b) + cos(a+b))…
