Question

已知函数f(x)= e的x次方/（1+a乘以x的平方）,其中a为正实数,求fx单调区间

Answer 1

f(x)=e^x/(1+ax^2)
f'(x)=[e^x(1+ax^2)-2axe^x]/(1+ax^2)^2=e^x(ax^2-2ax+1)/(1+ax^2)^2=ae^x[(x-1)^2+1/a-1]/(1+ax^2)^2
讨论a:
若0x1,或x