Homework Statement
Let X=C[0,\pi].
Define T:\mathcal{D}(T) \to X, Tx = x" where
\mathcal{D}(T) = \{ x \in X | x(0)=x(\pi)=0 \}.
Show that \sigma(T) is not compact.
Homework Equations
None.
The Attempt at a Solution
Well, functions sin(Ax) and sin(-Ax), for A=0,1,2,... are in the domain...