Given the function f (x) = LNX, G (x) = 1 / 2aX & # 178; + 2x, a ≠ 0. (1) if the function H (x) = f (x) - G (x) has monotone decreasing interval, find the value range of a; (2) if the function H (x) = f (x) - G (x) [1,4], find the value range of A Find the monotone interval of y = x √ (ax-x & # 178;) (a > 0)

Given the function f (x) = LNX, G (x) = 1 / 2aX & # 178; + 2x, a ≠ 0. (1) if the function H (x) = f (x) - G (x) has monotone decreasing interval, find the value range of a; (2) if the function H (x) = f (x) - G (x) [1,4], find the value range of A Find the monotone interval of y = x √ (ax-x & # 178;) (a > 0)

h(x)=xg(x)-2x=xln(x)-2x,x>0.
h'(x)=ln(x)+1-2=ln(x)-1,
H (x) increases monotonically
f(x)=ax^2/2 + 2x,
x> F '(x) = ax + 2 > = 0
x> When a = 1, a > = 0, it obviously meets the requirements
x>=1,a0.
ln(x)=ax^2 +(1-2a)x,
s(x)=ln(x) - ax^2 + (2a - 1)x,
1 / E0, s (x) monotonically increasing. S (1 / E)