Exercise 1:
Let V and W be vector spaces over a field F. Let α ∈ Hom(V, W) and β ∈ Hom(W, V) satisfy the condition that αβα = α.
If ω ∈ im(α), show that
α-1(ω) = {β(ω) + v - βα(v)|v∈V}
Exercise 2:
Let
α : R3 → R3 be the linear transformation given by
α :
Find ker(α) and im(α).
Exercise 3:
Let V be a finite-dimensional vector space over a field F and let α, β ∈ Hom(V, V) be linear transformations satisfying im(α) + im(β) = V = ker(α) + ker(β). Show that im(α) ∩ im(β) = {0V} = ker(α) ∩ ker(β).
Exercise 4:
Let V be a finitely-generated vector space over a field F and let α ∈ End(V).
Show that α is not monic if and only if there exists an endomorphism β ≠ σo.
V satisfying αβ = σ0.
Exercise 5:
Let V be a vector space over a field F and let α ∈ End(V). Show that ker(α) = ker(α2) if and only if ker(α) and im(α) are disjoint.
Exercise 6:
Let α and β be endomorphisms of a vector space V over a field F satisfying αβ = βα. Is ker(α) invariant under β?
Exercise 7:
Let V be a vector space over a field F and let α,β ∈ End(V). Show that α and β are projections satisfying ker(α) = ker(β) if and only if αβ = α and βα = β.
Exercise 8:
Let B = {1 + i, 2 +i}, which is a basis for C as a vector space over R. Let α be the endomorphism of this space defined by α: z-> z-. Find ΦBB(α).
Exercise 9:
Find a nonzero matrix A in M2x2(R) satisfying v ?. Av = 0 for all v ∈ R2.