In: Advanced Math
1. Let X and Y be non-linear spaces and T : X -->Y. Prove that if T is One-to-one then T-1 exist on R(T) and T-1 : R(T) à X is also a linear map.
2. Let X, Y and Z be linear spaces over the scalar field F, and let T1 ϵ B (X, Y) and T2 ϵ B (Y, Z). let T1T2(x) = T2(T1x) ∀ x ϵ X.
(i) Prove that T1T2 ϵ B (X,Y) is also a bounded linear mapping.
(ii) Prove that ǀǀT2T1ǀǀ ≤ ǀǀT2ǀǀ ǀǀT1ǀǀ
3. If X is an inner product space, then for arbitrary x, y ϵ X, ǀ< x, y>ǀ ≤ ǀǀxǀǀ ǀǀyǀǀ, prove that the inner product < ∙ > is a continuous function on X by X (Cartesian product) domain.