If $x$ and $y$ are real, and $x^2 + y^2 = 1,$ compute the maximum value of $(x + y)^2.$
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If $x$ and $y$ are real, and $x^2 + y^2 = 1,$ compute the maximum value of $(x + y)^2.$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
2
If $x$ and $y$ are real, and $x^2 + y^2 = 1,$ compute the maximum value of $(x + y)^2.$
train