fx=x^2+lnx-ax.f(x)在（0,1）上不单调求a取值

f(x) = x2+ lnx – ax,求导可得f ’(x) = 2x+ 1/x – a,因为函数f(x)在(0,1)上不单调,所以f ’(x) = 2x+ 1/x – a,在x∈(0,1)上可以取到正值和负值.记g(x) = 2x +1/x,所以g(x) ≥ 2√[2x(1/x)] = 2√2,（当且仅当2x = 1/x,即x = √2/2时取等号）,所以g(x)∈[2√2,+∞),要使得f ’(x) = 2x+ 1/x – a取到正值和负值的实数a的取值范围是(2√2,+∞) .