灵鹊做题网一道数学三角函数化简题
来源：学生作业帮 编辑：灵鹊做题网作业帮 分类：数学作业 时间：2024/04/30 20:58:31
一道数学三角函数化简题
(a sin派/5+b cos派/5)/(a cos派 /5 - b sin派/5)=(tan派/5+ b/a)/(1- b/a﹡ tan派/5)为什么啊.
(a sin派/5+b cos派/5)/(a cos派 /5 - b sin派/5)=(tan派/5+ b/a)/(1- b/a﹡ tan派/5)为什么啊.
右=(tanπ/5+b/a)/(1-b/a*tanπ/5)
右=(sinπ/5/cosπ/5+b/a)/(1-b/a*sinπ/5/cosπ/5) 分子、分母同乘a*cosπ/5
右=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)
左=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)
所以：
左=右
右=(sinπ/5/cosπ/5+b/a)/(1-b/a*sinπ/5/cosπ/5) 分子、分母同乘a*cosπ/5
右=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)
左=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)
所以：
左=右