Find the distance between the vertex of the graph of the equation $f(x) = x^2 - 8x + 15$ and the point $(0, 2)$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find the distance between the vertex of the graph of the equation $f(x) = x^2 - 8x + 15$ and the point $(0, 2)$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
5
Find the distance between the vertex of the graph of the equation $f(x) = x^2 - 8x + 15$ and the point $(0, 2)$.
train