f g E R C
f◦g= Id
Ker(g◦f) = Ker fIm(g◦f) = Img
E= Ker f⊕Img
g=f−1
(g◦f)◦(g◦f)g◦f
HKE
a E H
H⊕Vect(a) = E
HKE D
H
D H E
HKE
F E H
F=H F =E
f, g ∈E∗Ker f= Ker g α ∈K
f=αg
e= (e1, . . . , en)KE
n∈N∗
∀f∈E∗, f(e1) = . . . =f(en) = 0 =⇒f= 0
e E
EKV E
f∈ L(E)
V⊂f(V) =⇒f(V) = V
f∈ L(E, F ) (x1, . . . , xp)
E
rg(f(x1), . . . , f(xp)) = rg(x1, . . . , xp)
f:R3→R3f(x, y, z)=(y−z, z −x, x −y)
f:R4→R3f(x, y, z, t) = (2x+y+z, x +y+t, x +z−t)
f:C→Cf(z) = z+i¯zC R
EKn≥1f
E p fp=˜
0
x∈E
x, f(x), f2(x), . . . , fp−1(x)
fn=˜
0
f n
(I, f, f2, . . . , fn2)
f
E