tg(?+?)=(tg?+tg?)/(1–tg?·tg?); tg(?-?)=(tg?–tg?)/(1+tg?·tg?) ctg(?+?)=(ctg?·ctg?–1)/(ctg?+ctg?); ctg(?+?)=(ctg?·ctg?+1)/(ctg?–ctg?) sin?+sin?=2sinЅ(?+?)cosЅ(?-?); sin?-sin?=2cosЅ(?+?)sin Ѕ(?-?) cos?+cos?=2cosЅ(?+?)cosЅ(?-?); cos?-cos?=-2sinЅ(?+?)sin Ѕ(?-?) a·sinx+b·cosx=((aІ+bІ)sin(x+?), где tg?=b/a tg? ( tg?=sin(?+?)/(cos?·cos?); ctg? ( ctg?=sin(?(?)/(sin?·sin?) sinІ?–sinІ?=cosІ?–cosІ?=sin(?+?)sin(?-?) cosІ?–sinІ?=cosІ?–sinІ?=cos(?+?)cos(?-?) sin?·sin?=Ѕ[cos(?-?)–cos(?+?)]; cos?·cos?=Ѕ[cos(?-?)+cos(?+?)] sin?·cos?=Ѕ[sin(?+?)+sin(?-?)] tg?·tg?=(tg?+tg?)/(ctg?+ctg?)=-(tg?–tg?)/(ctg?–ctg?) ctg?·tg?=(ctg?+tg?)/(tg?+ctg?)=-(ctg?–tg?)/(tg?–ctg?) ctg?·ctg?=(ctg?+ctg?)/(tg?+tg?)=-(ctg?–ctg?)/(tg?–tg?) sinЅ?=((((1–cos?)/2); sin?=(2tgЅ?)/(1+tgІ Ѕ?) sin2?=2 sin?·cos?; sin3?=3sin?–4sinі? sinІ?=Ѕ(1–cos2?); sinі?=(3 sin? – sin 3?) / 4 cosЅ?=(([(1+cos?)/2]; cos?=(1–tgІ Ѕ?)/(1+tgІ Ѕ?) cos2?=cosІ?–sinІ?=1–2 sinІ?=2cosІ?–1; cos3?=4cosі?–3 cos? cosІ?=Ѕ(1+cos2?);cosі?=(3cos?+cos3?)/4 tgЅ?=sin?/(1+cos?)=(1–cos?)/sin?= ((((1–cos?)/(1+cos?)) tg?=(2tgЅ?)/(1–tgІ Ѕ?); tg2?=(2tg?)/(1–tgІ?)=2/(ctg?–tg?) tg3?=(3tg?–tgі?)/(1–3tgІ?)=tg?·tg(?/3+?)·tg(?/3–?) ctgЅ?=sin?/(1–cos?)=(1+cos?)/sin?=((((1+cos?)/(1–cos?)) ctg?=(ctgІ Ѕ?–1)/2ctg Ѕ?; ctg2?=(ctgІ?–1)/2ctg?=Ѕ(ctg?–tg?) ctg3?=(3ctg?–ctgі?)/(1–3 ctgІ?) tg(јп+?)=(sin?+cos?)/(sin?–cos?); tg(јп–?)=(sin?–cos?)/(sin?+cos?)