1) f'(x)=m(x²+n-2x²)/(x²+n)²=m(n-x²)/(x²+n)²由题意,f'(1)=2,得n-1=0,即n=1f(1)=2,得m/(1+n)=2,得m=2(1+n)=4即f(x)=4x/(x²+1)2)由上,f'(x)=4(1-x²)/(x²+1)...