
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the function $f\left(x\right)=1-2{a}^{x\;}-{a}^{2x}\left(a &gt; 1\right) $

(1) Find the range of the function $f(x)$;

(2) If $x\in\left[-2,1\right]$, the minimum value of the function $f(x)$ is $-7$, find the maximum value of $f(x)$.

Present the answer in LaTex format: \boxed{Your answer}
user