The set of linear transformations between two vector spaces is a vector space.
Theorem: The set of all linear transformations from a vector space (V) to a vector space (W) (over the same field (\mathbb{F})), denoted (\mathcal{L}(V, W)) or ( ext{Hom}(V, W)), is itself a vector space over (\mathbb{F}).
Operations:
- Addition: ((S + T)(\mathbf{v}) = S(\mathbf{v}) + T(\mathbf{v}))
- Scalar multiplication: ((cT)(\mathbf{v}) = c \cdot T(\mathbf{v}))
Zero vector: The zero transformation (Z(\mathbf{v}) = \mathbf{0}) for all (\mathbf{v}).
Verification: The sum and scalar multiple of linear transformations are themselves linear transformations.
Dimension: If (\dim V = n) and (\dim W = m), then (\dim \mathcal{L}(V, W) = mn). This is isomorphic to (M_{m imes n}(\mathbb{F})) via the matrix representation map.