I know this is easy, but I can't find the way to prove this:

Let V,\Vert . \Vert _V) \longrightarrow (W,\Vert . \Vert _W)" alt="lV,\Vert . \Vert _V) \longrightarrow (W,\Vert . \Vert _W)" /> be a linear transformation. Show that if is continous at then there exists such that