函数f(x)=㏒a(x3-ax) (a>0,a≠1)
f'(x)=(3x^2-a)㏒a(e)/(x^3-ax),函数f(x)=㏒a(x3-ax) (a>0,a≠1)在区间(-0.5,0 )内单调递增,也就是说0.5