1.x = log3(36)= 2 log3(6)= 2lg 6/(lg3);
y = log4(36)= 2 log4(6)= log2(6)= lg6/lg2 .
therefore
(2/x)+( 1/y)
= monotonically increasing,
The minimum value is h (a) = g (1/3) = (28/9)-(2a/3);
When 1/3
h(a)=g(a)=3-a^2;
When a & gt=3, g(x) decreases monotonically in this interval,
The minimum value is h(a)=g(3)= 12-6a.
(2) By (1)
h(a)=(28/9)-(2a/3)(a & lt; = 1/3)
h(a)=3-a^2( 1/3 & lt; a & lt3)
h(a)= 12-6a(a & gt; =3)
Let such m and n exist and satisfy m >;; n & gt3。
When a∈[n, m],
The function h(a)= 12-6a is a monotonically decreasing linear function,
The maximum value is h (n) =12-6n;
The minimum value is h(m)= 12-6m.
therefore
12-6n=m^2
12-6m=n^2
Solve m and n at the same time, and then make a choice according to the value range (3, positive infinity).
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