作业帮怎样从-[1-2sin²(x-π/12)]得到-cos(2x-π/6)?
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/05 21:23:46
![怎样从-[1-2sin²(x-π/12)]得到-cos(2x-π/6)?](/uploads/image/z/5489343-63-3.jpg?t=%E6%80%8E%E6%A0%B7%E4%BB%8E-%5B1-2sin%26%23178%3B%28x-%CF%80%2F12%29%5D%E5%BE%97%E5%88%B0-cos%282x-%CF%80%2F6%29%3F)
怎样从-[1-2sin²(x-π/12)]得到-cos(2x-π/6)?
怎样从-[1-2sin²(x-π/12)]得到-cos(2x-π/6)?
怎样从-[1-2sin²(x-π/12)]得到-cos(2x-π/6)?
cos2x=(cosx)^2-(sinx)^2=1-2(sinx)^2
∴-[1-2sin(x-π/12)]=-cos(2x-π/6)