
r = a + r
e
r
∗
= r
e
+ c = r
e
+ a cos ϕ + b sin ϕ.
r
∗
= Λ ◦ r ◦
e
Λ
(27.4)
=
³
r ◦ Λ + 2[e sin
ϕ
2
, r]
´
◦
e
Λ = r ◦
1
z}|{
Λ ◦
e
Λ +2b ◦
e
Λ sin
ϕ
2
=
= r + 2b ◦
³
cos
ϕ
2
− e sin
ϕ
2
´
sin
ϕ
2
= r + b sin ϕ − a(1 − cos ϕ) =
= r − a
|{z}
r
e
+ a cos ϕ) + b sin ϕ
| {z }
c
.
b ◦ e = −(b, e) + [b, e] = −([e, r], e) + [b, e] = [b, e] = a.
¥
r
Λ
−→ r
∗
M
−→ r
∗∗
,
r
N=?
−−→ r
∗∗
.
Λ r r
∗
M r
∗
r
∗∗
N
r r
∗∗
r
∗
= Λ ◦r ◦
e
Λ
r
∗∗
= M ◦ r
∗
◦
f
M = M ◦ Λ ◦ r ◦
e
Λ ◦
f
M
(27.11)
= M ◦ Λ ◦ r ◦
^
M ◦ Λ = N ◦ r ◦
e
N,
N = M ◦ Λ
Λ M
N = M ◦ Λ
n
r
Λ
1
−→ ···
Λ
n
−→ r
∗
r
N
−→ r
∗
,
N = Λ
n
◦ ··· ◦ Λ
1
. (28.2)