f(x)=2x-1,g(x)=x²+1,则f[g(x)]=_____,g[f(x)]=_____.
问题描述：
f(x)=2x-1,g(x)=x²+1,则f[g(x)]=_____,g[f(x)]=_____.
答
f[g(x0]
=2(x²+1)-1
=2x²+1
g[f(x)]
=(2x-1)²+1
=4x²-4x+2