三角形正弦余弦正切公式sin(α+β）=sin(α-β）=tan(α+β）=tan(α-β）=sin2α=cos2α=t

Sin(A+B)=SinA*CosB+SinB*CosA
Sin(A-B)=SinA*CosB-SinB*CosA
Cos(A+B)=CosA*CosB-SinA*SinB
Cos(A-B)=CosA*CosB+SinA*SinB
Tan(A+B)=(TanA+TanB)/(1-TanA*TanB)
Tan(A-B)=(TanA-TanB)/(1+TanA*TanB
sin(2α)=2sinα·cosα=2/(tanα+cotα)
cos(2α)=cos^2(α)-sin^2(α)=2cos^2(α)-1=1-2sin^2(α)
tan(2α)=2tanα/[1-tan^2(α)]

1.诱导公式 sin(-a)=-sin(a)
cos(-a)=cos(a)
sin(2π-a)=cos(a)
cos(2π-a)=sin(a) s
in(2π+a)=cos(a)
cos(2π+a)=-sin(a)
sin(π-a)=sin(a) cos(π-a)=-cos(a) sin(π+a)=-sin(a) cos(π+a)=-cos...