If $x$ and $y$ are positive real numbers for which $(x + y)^2 + (x - y)^2 = 10$ and $(x + y)^4 + (x - y)^4 = 98$, what is the value of $xy$? Express your answer in simplest radical form.
Question:
If $x$ and $y$ are positive real numbers for which $(x + y)^2 + (x - y)^2 = 10$ and $(x + y)^4 + (x - y)^4 = 98$, what is the value of $xy$? Express your answer in simplest radical form.
Answer:
Let's think step by step.

user
\sqrt{6}
If $x$ and $y$ are positive real numbers for which $(x + y)^2 + (x - y)^2 = 10$ and $(x + y)^4 + (x - y)^4 = 98$, what is the value of $xy$? Express your answer in simplest radical form.
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