F(x) derivative = 2/x-2x = 2/x (1-x 2) x > 0.

0<x< in 1, derivative >; 0, function increasing function, when x> 1, the derivative is less than 0, and the function is subtracted.

The maximum value of f(x) is f( 1)=- 1.

(2)g(x)=alnx-x^2+ax

Derivative =a/x-2x+a

=- 1/x(2x^2-ax-a)x & gt； 0

G(x) is not monotonic at (0,3), which means that the derivative has a solution at (0,3).

That is, 2x 2-ax-a = 0 has a solution.

Discriminant ≥0, axis ∈

The answer is a∈[0, 12]