a) Prove that if $G$ is reconstructible, then $\overline G$ is reconstructible.
b)Prove that every graph of order $n≥3$ whose complement is disconnected is reconstructible.
For a), the book tell me to consider $\overline{ \overline G -v}=G-v$. But I still can't see how this help me.
For b), it's kind straight forward, every disconnected graph of order at least $3$ is reconstructible, so $\overline G$ is reconstructible. Note that $G=\overline{\overline G}$. From the result of a), $G$ is reconstructibble.