1.等差数列{an}满足a1+a(2n-1)=2n,f(n)=S2n-Sn,∴a1=1,a(2n-1)=2n-1,a3=1+2d=3,d=1,∴an=n,f(n)=S2n-Sn=n(2n+1)-n(n+1)/2=(3n+n)/2,f(n+1)=(3(n+1)+n+1)/2=f(n)+3n+2>f(n).2.2^x-2^（-x）-t=2恒成立,记y=2^x-2^（-x...