f(x)=√(x^2+2) > √(x^2)=x
所以f(x)-x >0,因为[√(x^2+2)-√(x^2)][√(x^2+2)+√(x^2)]=2
f(x)-x=√(x^2+2)-√(x^2)= 2/[√(x^2+2)+√(x^2)]< 2/[√(x^2)+√(x^2)]=1/x
0
所以 1002+1003+...+2005=(1002+2005)*1004/2=1509514
1509514
令a=1求函数f(x)在x=2处的切线方程要过程问题补充:是f(x)=x2 22y-10-2aln2=(7 a)*(x-2) (a 7)x-2y-4 2aln2-2a=0