f[(x+1)/x]=(x+1)/x^2,令（x+1）/x=t;tx=x+1;(t-1)x=1;x=1/(t-1);f(t)=(1/(t-1)+1)/1/(t-1)²=t(t-1);∴f(x)=x(x-1)=x²-x;;∴f′(x)=2x-1;很高兴为您解答,skyhunter002为您答疑解惑如果本题有什么不明白可...