
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 power function $y=f(x)$ passes through the point $(9, \frac{1}{3})$,

(1) Find the expression for $f(x)$;

(2) Calculate the value of $f(25)$;

(3) If $f(a)=b$ $(a,b>0)$, then how can $a$ be expressed in terms of $b$?

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