sin(α+β)=sinαcosβ+cosαsinβ
sin(α-β)=sinαcosβ-cosαsinβ
sin(π/2-α)=cosα
sin(π/2+α)=cosα
sin(3π/2+α)=- cosα
sin(π-α)=sinα
sin(π+α)= -sinα
正弦函数sin公式,在线求解答
sin(α+β)=sinαcosβ+cosαsinβ
sin(α-β)=sinαcosβ-cosαsinβ
sin(π/2-α)=cosα
sin(π/2+α)=cosα
sin(3π/2+α)=- cosα
sin(π-α)=sinα
sin(π+α)= -sinα
sin(pi/2a)=cosa;cos(pi/2a)=sina(即:奇变偶不变,符号看象限)