Can you please help me finding an exact description of the set:
$$ E_{R}=\{\cos{z} | z \in \mathbb{C}, |z|>R\} $$
For any $0
My feeling is the $E_R = \mathbb{C}$, for any $R$, but I don't know how to show it, if it's true.
Can you please help me finding an exact description of the set:
$$ E_{R}=\{\cos{z} | z \in \mathbb{C}, |z|>R\} $$
For any $0
My feeling is the $E_R = \mathbb{C}$, for any $R$, but I don't know how to show it, if it's true.