I'm having trouble with this question:
Given any language L is a subset of $\{0,1\}^*$, define the language
$$\text{unary}(L) =\{0^{1x} | x \in L\}$$
The language $\text{unary}(L)$ is said to be unary since it is a subset of $ 0^*$. Show that $L$ is recursive if and only if $\text{unary}(L)$ is recursive.