作业帮y=cos2x +2sinx -3的值域= 1-2(sinx)^2+2sinx -3= -2(sinx-1/2)^2 - 3/2 值域为[-6,-3/2]是怎么算出来的,
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/12 12:44:55
![y=cos2x +2sinx -3的值域= 1-2(sinx)^2+2sinx -3= -2(sinx-1/2)^2 - 3/2 值域为[-6,-3/2]是怎么算出来的,](/uploads/image/z/12505677-69-7.jpg?t=y%3Dcos2x+%2B2sinx+-3%E7%9A%84%E5%80%BC%E5%9F%9F%3D+1-2%28sinx%29%5E2%2B2sinx+-3%3D+-2%28sinx-1%2F2%29%5E2+-+3%2F2+%E5%80%BC%E5%9F%9F%E4%B8%BA%5B-6%2C-3%2F2%5D%E6%98%AF%E6%80%8E%E4%B9%88%E7%AE%97%E5%87%BA%E6%9D%A5%E7%9A%84%2C)
y=cos2x +2sinx -3的值域= 1-2(sinx)^2+2sinx -3= -2(sinx-1/2)^2 - 3/2 值域为[-6,-3/2]是怎么算出来的,
y=cos2x +2sinx -3的值域
= 1-2(sinx)^2+2sinx -3
= -2(sinx-1/2)^2 - 3/2 值域为[-6,-3/2]是怎么算出来的,
y=cos2x +2sinx -3的值域= 1-2(sinx)^2+2sinx -3= -2(sinx-1/2)^2 - 3/2 值域为[-6,-3/2]是怎么算出来的,
y= -2(sinx-1/2)^2 - 3/2
因为-1<=sinx<=1
所以sinx=1/2,最大-3/2
sinx=-1,最小是-6