宸茬煡tanα=-1/2,那么sin²α+2sinαcosα-3cos²α如果tanα=-1/2,那么sin²α+2sinαcosα-3cos²α
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/01 23:19:18
![宸茬煡tanα=-1/2,那么sin²α+2sinαcosα-3cos²α如果tanα=-1/2,那么sin²α+2sinαcosα-3cos²α](/uploads/image/z/1332859-67-9.jpg?t=%E5%AE%B8%E8%8C%AC%E7%85%A1tan%CE%B1%3D-1%2F2%2C%E9%82%A3%E4%B9%88sin%26%23178%3B%CE%B1%2B2sin%CE%B1cos%CE%B1-3cos%26%23178%3B%CE%B1%E5%A6%82%E6%9E%9Ctan%CE%B1%3D-1%2F2%2C%E9%82%A3%E4%B9%88sin%26%23178%3B%CE%B1%2B2sin%CE%B1cos%CE%B1-3cos%26%23178%3B%CE%B1)
宸茬煡tanα=-1/2,那么sin²α+2sinαcosα-3cos²α如果tanα=-1/2,那么sin²α+2sinαcosα-3cos²α
宸茬煡tanα=-1/2,那么sin²α+2sinαcosα-3cos²α
如果tanα=-1/2,那么sin²α+2sinαcosα-3cos²α
宸茬煡tanα=-1/2,那么sin²α+2sinαcosα-3cos²α如果tanα=-1/2,那么sin²α+2sinαcosα-3cos²α
sin²α+2sinαcosα-3cos²α=(sin²α+2sinαcosα-3cos²α)/(sni²a+cos²a)
再给分子,分母同时除cos²a可解.