sin(π-α)-cos(π+α)=根号2/4(0
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/26 06:13:12
![sin(π-α)-cos(π+α)=根号2/4(0](/uploads/image/z/8800606-46-6.jpg?t=sin%28%CF%80-%CE%B1%29-cos%28%CF%80%2B%CE%B1%29%3D%E6%A0%B9%E5%8F%B72%2F4%280)
sin(π-α)-cos(π+α)=根号2/4(0
sin(π-α)-cos(π+α)=根号2/4(0
sin(π-α)-cos(π+α)=根号2/4(0
因为 sin(π-α)=sinα cos(π+α)=-cosα
所以原式=sinα+ cosα=根号二/4
则(sinα+ cosα)^2=1/8 即1+2sinαcosα=1/8
所以2sinαcosα=-7/8 由此得出2/π