问题
填空题
cos
|
答案
cos
cosπ 17
cos2π 17
cos4π 17 8π 17
=cos
cosπ 17
cos2π 17
cos4π 17
(24sin8π 17
)π 17 24sin π 17
=sin 16π 17 24sin π 17
=1 16
cos
|
cos
cosπ 17
cos2π 17
cos4π 17 8π 17
=cos
cosπ 17
cos2π 17
cos4π 17
(24sin8π 17
)π 17 24sin π 17
=sin 16π 17 24sin π 17
=1 16