f(x)=(a^x-1)/(a^x+1)∵a＞0∴a^x＞0∴a^x+1＞1∴定义域x∈Rf(x)=(a^x-1)/(a^x+1) = (a^x+1-2)/(a^x+1) = 1 - 2/(a^x+1) ∵a^x+1＞1∴2＞2/(a^x+1)＞0∴ -1＜ 1 - 1/(a^x+1) ＜1∴值域（-1,1) f(-x)=(a^(-x)-1)/(a^(...∵a^x+1＞1∴1＞1/(a^x+1)＞0所以,2>2/(a^x+1)>0