求证:2sinα+sin2α=2sin^3α/(1-cosα)
来源：学生作业帮助网 编辑：六六作业网 时间：2024/05/28 02:41:34
求证:2sinα+sin2α=2sin^3α/(1-cosα)求证:2sinα+sin2α=2sin^3α/(1-cosα)求证:2sinα+sin2α=2sin^3α/(1-cosα)2sina+s
求证:2sinα+sin2α=2sin^3α/(1-cosα)
求证:2sinα+sin2α=2sin^3α/(1-cosα)
求证:2sinα+sin2α=2sin^3α/(1-cosα)
2sina+sin2a
=2sina+2sinacosa
=2sina(1+cosa)=2sin^3a(1+cosa)/sin^2a
=2sin^3a(1+cosa)/(1-cos^2a)
=2sin^3a/(1-cosa)