sinα=1/3 cos2α=
问题描述:
sinα=1/3 cos2α=
答
sinα=1/3
cos2α=1-2sin^2α=1-2/9==7/9
sinα=1/3 cos2α=
sinα=1/3
cos2α=1-2sin^2α=1-2/9==7/9