Simplify
\[\frac{\sin^4 x + \cos^4 x - 1}{\sin^6 x + \cos^6 x - 1}.\]
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Simplify
\[\frac{\sin^4 x + \cos^4 x - 1}{\sin^6 x + \cos^6 x - 1}.\]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\frac{2}{3}
Simplify
\[\frac{\sin^4 x + \cos^4 x - 1}{\sin^6 x + \cos^6 x - 1}.\]
train