化简cos(90°-α)/sin(270°-α)*sin(360°-α)*sin(180°-α)

问题描述:

化简cos(90°-α)/sin(270°-α)*sin(360°-α)*sin(180°-α)

cos(90°-α)/sin(270°-α)*sin(360°-α)*sin(180°-α)
=sinα/(-cosα)*(-sinα)*sinα=1/sinacosa