The increase and decrease of compound function is similar to the law of positive and negative product,
Namely, increasing function and increasing function are compounded into increasing function.
Increasing function and subtraction function compound subtraction function.
The subtraction function and the combination of subtraction functions form a increasing function.
Exponential function: an increasing function when a> 1 0.
Quadratic function: When the opening is upward, the left side of the symmetry axis is the decreasing function and the right side is the increasing function.
On this topic: suppose 0; =0, you can get 0 < a< 1 in line with the meaning of the question.
Assuming a> 1, the indicator part is required to be increasing function A/2.
Therefore, the value range of A that finally meets the meaning of the question is (0, 1).