sin2α+cos2α =11+tg2α=1/cos2α1+ctg2α=1/sin2αtgα *ctgα=1sin(α+β)=sinαcosβ +cosαsinβsin(α-β)=sinαcosβ-cosαsinβcos(α+β)=cosαcosβ-sinαsinβcos(α-β)=cosαcosβ+sinαsinβtg(α+β)=(tgα+tgβ)/(1-tgαtgβ)tg(α-β)=(tgα-tgβ)/(1+tgαtgβ)sin2α=2sinαcosβcos2α=cos2α-sin2α= 2cos2α-1=1-2 sin2αtg2α=2tg/(1-tg2α)sin2α=(1-cos2α)/2cos2α=(1+cos2α)/2tg(α/2)=sinα/(1+cos α)=(1-cos α)/sin αsin3α=3sinα-4sin3αcos3α=4cos3α-3cosαtg3α=(3tgα-tg3α)/(1-3tg2α)ctg3α=(ctg3α-3ctgα)/(3ctg2α-1)sin α+sin β=2sin[(α+β)/2]cos[(α-β)/2]sin α-sin β=2sin[(α-β)/2]cos[(α+β)/2]cosα+cosβ=2cos[(α+β)/2]cos[(α-β)/2]cosα-cosβ=-2sin[(α+β)/2]sin[(α-β)/2]tgα±tgβ=sin(α±β)/cosαcosβctgα±ctgβ=sin(β±α)/sinαsinβsinαcosβ=1/2*(sin(α+β)+sin(α-β))cosαcosβ=1/2*(cos(α+β)+cos(α-β))sinαsinβ=1/2*(cos(α-β)+cos(α+β))