
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 line $x-my-4=0$ and the circle $O:x^{2}+y^{2}=5$, which intersect at points $A$ and $B$.<br/>$(1)$ For what value of $m$ is the chord length $4$;<br/>$(2)$ If $\overrightarrow{OA}•\overrightarrow{QB}≤0$, find the range of values for $m$.

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