1)得f'(x)=e^x{1+(4/3)x^2-(8/3)x}/{1+(4/3)x^2}^2因为求极值点，则x=0.5或1.5(2)f'(x)=e^x(ax^2-2ax+1)/(1+ax^2)^2因为是单调函数，所以只要使ax^2-2ax+1恒大于0或是恒小于0所以0
