函数f(x)=a的x方(a大于0,a不等于1)满足f(2)=81,则f(-1/2)的值

问题描述:

函数f(x)=a的x方(a大于0,a不等于1)满足f(2)=81,则f(-1/2)的值

f(x)=a的x方(a大于0,a不等于1)
f(2)=81即a²=81,则a=9
f(-1/2)=a的(-1/2)方
=1/根号a
=1/根号9
=1/3