1、三角函数转换公式1、诱导公式:sin(-α)=-sinα;cos(-α)=cosα;sin(π/2-α)=cosα;cos(π/2-α)=sinα; sin(π/2+α)=cosα;cos(π/2+α)=-sinα;sin(π-α)=sinα;cos(π-α)=-cosα; sin(π+α)=-sinα;cos(π+α)=-cosα;tanA=sinA/cosA;tan(π/2+α)=-cotα;tan(π/2-α)=cotα;tan(π-α)=-tanα;tan(π+α)=tanα2、两角和差公式: sin(AB)=sinAcosBcosAsinB cos