1.f(x)=(x/2)^2-x/2-1
2.f(x)=1/(1+2x)
3.f(x)=(x-1)/5+5(x-1)
4.设f(x)=ax^2+bx+c.由已知得f(x)=(5x^2)/4-5x/2-3
5.f[f(x)]=16x+5 f{f[f(x)]}=64x+21
1.f(x)=(x/2)^2-x/2-1
2.f(x)=1/(1+2x)
3.f(x)=(x-1)/5+5(x-1)
4.设f(x)=ax^2+bx+c.由已知得f(x)=(5x^2)/4-5x/2-3
5.f[f(x)]=16x+5 f{f[f(x)]}=64x+21