
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
Define $f(x)$ as an even function on $\mathbb{R}$, and for $x \geq 0$, $f(x) = x^3$. If for any $x \in [2t-1, 2t+3]$, the inequality $f(3x-t) \geq 8f(x)$ always holds, then the range of the real number $t$ is \_\_\_\_\_\_.

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