If $x^2+bx+16$ has at least one real root, find all possible values of $b$. Express your answer in interval notation.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If $x^2+bx+16$ has at least one real root, find all possible values of $b$. Express your answer in interval notation.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
(-\infty,-8]\cup [8,\infty)
If $x^2+bx+16$ has at least one real root, find all possible values of $b$. Express your answer in interval notation.
train