f(x)是奇函数, ∴f(x)+f(-x)=ax+b/x+c-ax-b/x+c=2c=0恒成立, ∴c=0, f(x)=ax+b/xf(1)=a+b=3①, f(2)=2a+b/2=3②结合①②得 a=1, b=2, f(x)=x+2/x1)f'(x)=1-2/x^2令f'(x)>0, x>√2; 令f'(x)<0, 0
