For any $f\in L^2(\mathbb{R})$, we define $A: L^2(\mathbb{R})\rightarrow L^2(\mathbb{R})$ by $A(f)(x)=f(|x|)$. How to calculate the operator norm of $A$ and what is the adjoint of $A$?
2026-03-27 07:20:01.1774596001
How to calculate the operator norm $A:L^2(\mathbb{R})\rightarrow L^2(\mathbb{R})$
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