函数f(x)=ax-1满足f[f(x)]﹦x,则常数a等于

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/14 11:53:10

函数f(x)=ax-1满足f[f(x)]﹦x,则常数a等于
函数f(x)=ax-1满足f[f(x)]﹦x,则常数a等于

函数f(x)=ax-1满足f[f(x)]﹦x,则常数a等于
∵f(x)=ax-1
∴f[f(x)]=f(ax-1)
=a(ax-1)-1
=a²x-a-1
∵f[f(x)]=x
∴a²x-a-1=x ==>a²=1,-a-1=0
==>a=-1
故a=-1.