Let $F$ be the multiplicative group of all functions mapping $\mathbb{R}$ into $\mathbb{R}$, that do not assume the value $0$ at any point of $\mathbb{R}$. Now let $K$ be the subgroup of $F$ consisting of the nonzero constant functions.
How can I find a subgroup of $F$ to which $F/K$ is isomorphic?