作业帮证明：[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2x/2cosy^2
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 09:25:55
![证明：[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2x/2cosy^2](/uploads/image/z/6896791-55-1.jpg?t=%E8%AF%81%E6%98%8E%EF%BC%9A%5Btan%28x%2By%29-tanx%5D%2F1%2Btanxtan%28x%2By%29%3Dsin2x%2F2cosy%5E2)
证明：[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2x/2cosy^2
证明：[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2x/2cosy^2
证明：[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2x/2cosy^2
左边=tan(x+y-x)=tany
右边=2sinycosy/2cos^2y
=siny/cosy
=tany
左边=右边
[tan(x+y)-tanx]/1+tanxtan(x+y)=sin2y/2cosy^2
啥东东啊？