若函数g(x)=1-2x,f[g(x)]=1-x^2/x^2,(x不等于0),求f(1/2)

问题描述:

若函数g(x)=1-2x,f[g(x)]=1-x^2/x^2,(x不等于0),求f(1/2)

g(x)=1-2x =1/2
x=1/4
带入
f[g(x)]=1-x^2/x^2
=[1-(1/4)^2]/(1/4)^2
=15