已知tan(π+α)=3,则sin(π-α)+cos(-α)sin(π+α)-c 发布时间:2017-04-15 02:12 │ 来源:www.tikuol.com 题型:选择题 问题: 已知tan(π+α)=3,则sin(π-α)+cos(-α)sin(π+α)-cos(π+α)的值为( )A.2B.-2C.3D.-3