## Subspaces and spans

Hey.

I have some exercise I have no idea how to start and what to do:

Let R^R be a vector space above $\mathbb{R}$.
Prove that $\forall f \in W$ there are $a, b \in \mathbb{R}$ such that $f(x) = asin(x + b) \ \ \ \ \forall x\in \mathbb{R}$

Thank you!