f(x)& lt； -f(y)=f(-y)，∫x & gt； -y, ∴f(x) decreases, max=f(-3)=2, min = f (3) =-2;

Question 2: f(x)=x+b/x+a, ∫f(x) decreases at (0, 1) and increases at (1, +∞), ∴ b = 1, min.

∴a= 1。

The third question: (1)∵(f(m)+f(n))/(m+n)>0, ∴ m+n >; 0, then f(m)+f(n)>0, and f(x) increases in (-1, 1),-1

(2)max=f( 1)= 1，T2-2at+ 1 & gt； = 1, t(t-2a)>=0, residual score-1

Question 4: Set m>n, f (m)-f (n) = g (m)-1/g (m)+1-g (n)-1=

∵g(x)>0,∴ 1/(2g(m+n)+ 1)>； 0, ∴g(x) increasing, ∴ g (m) > g(n)∴f(m)-f(n)>； 0,∴f(x) increases