sin(π/4+α)sin(π/4-α)=1/6 求sin2α
来源：学生作业帮助网 编辑：六六作业网 时间：2024/11/17 17:49:08
sin(π/4+α)sin(π/4-α)=1/6求sin2αsin(π/4+α)sin(π/4-α)=1/6求sin2αsin(π/4+α)sin(π/4-α)=1/6求sin2α诱导公式sin(π/
sin(π/4+α)sin(π/4-α)=1/6 求sin2α
sin(π/4+α)sin(π/4-α)=1/6 求sin2α
sin(π/4+α)sin(π/4-α)=1/6 求sin2α
诱导公式
sin(π/4+α)sin(π/4-α)=1/6
sin(π/4+α)cos(π/4+α)=1/6
2sin(π/4+α)cos(π/4+α)=1/3
sin[2(π/4+α)]=1/3
cos2α=1/3
由(cos2α)^2+(sin2α)^2=1
sin2α=±2√2/9