
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 $f(x) = \log_{4}(4^{x} + 1) + kx$ ($k \in \mathbb{R}$) is an even function.  
(1) Find the value of $k$;  
(2) Let $g(x) = \log_{4}$, if the graph of function $f(x)$ and $g(x)$ have exactly one common point, find the range of values for the real number $a$.

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