i` b7q`k xbqmb 77bmb. bm+b/2mx 2 t ` hh2hbbkqferrario/geo1-2014/w9.pdf · so4 poy i` b7q`k xbqmb...
TRANSCRIPT
X Y Kf : X ! Y
x " X#!X ! #!Y
v " #!X $! f (x + v) # f (x) " #!Y
X = Y = K = R
x $! ax + b
f : X ! Y
x $! x + v
f : X ! Y Kx0 " X
Lx0 : v " #!X $! f (x0 + v) # f (x0) "#!Y
Lx x#!f
x " X v $! f (x +v) # f (x) #!X ! #!Y x " X
x0 L :#!X ! #!Y
L(v) = v $! f (x0 + v) # f (x0).
v " #!X
f (x + v) # f (x) = f!x0 +##!x0x + v
"# f
!x0 +##!x0x
",
f (x + v) # f (x) = f!x0 +##!x0x + v
"# f (x0)
#!f!x0 +##!x0x
"# f (x0)
"
= L(##!x0x + v) # L(##!x0x)
= L(##!x0x) + L(v) # L(##!x0x)
= L(v)v
f : X ! YK X = Y
f : X ! Y#!f :#!X ! #!Y #!f
f #1 : Y ! X
X K GA(X)
X K nX %=
An(K) K
x0 x1 xn Xf : An(K) ! X
(!1, . . . , !n) $! x0 +n#
i=1!i###!x0xi " X.
f x0
xn
&###!x0x1, . . . ,###!x0xn'
n f (0 + v) # f (0)f
f : Ad(K) ! An(K)
f (x) = Ax + b = A(x # 0) + (b # 0),
A n ( d b Kn
z = (0, . . . , 0) " Ad(K)
f (z+ v)# f (z) A : Kd ! Kn
f (z + v) # f (z) = Av f (z) = b # 0
f (z + v) = Av+ b,
f (x) = Ax + b Kd
X n Yd p0, p1, . . . , pn
X n + 1 q0, q1, . . . , qn Yf : X ! Y f (pi) = qi i = 0, . . . , n
X %= An(K)
An(K) 0, e1, . . . , en
ei Kn
Y f (x) =Ax + b A
q1 # q0 qn # q0 bq0 Ai, j A bi
b i = 1 . . . n
f (pi) = Aei + b =
$%%%%%%%%%%%%%%%%%%%%%%%&
A1,i + b1
A2,i + b2
Ad,i + bd
'((((((((((((((((((((((()
f (p0) = b Ai, j
S ) X = An(K)
df : X ! An#d(K)
S = {x " X : f (x) = 0}.
f : X ! An#d(K) {x " X :
f (x) = 0} X d
W S P S
S = P +W .
W * W #!XW * #!X
#!X = W +W *.
dim(W) = d dim(W *) = n # d x " X x # P
x # P = w +w*
w " W w* " W * L :#!X !
W * L(w+w*) = w* L ker L = W W *
W * %= Kn#d
An#d(K) Kn#d f : X ! An#d(K)
f (x) = 0 + L(x # P) " An#d(K)
0 Kn#d
f (x) = 0 ,- x # P " W
,- x " P +W
,- x " S,
S = {x " X : f (x) = 0}f : X ! An#d(K) S = {x "
X : f (x) = 0} x0 " S L :#!X = Kn ! Kn#d Lv = f (x0 +
v) # f (x0) W ) Kn
n # (n # d) = d x0 " S f (x0) = 0x0 + v S
f (x0 + v) = 0 ,- Lv = 0 ,- v " W ,
S = x0 +W W d
2 3A2(R) ax + by + c = 0 A3(R) ax + by + cz + d =
0 A3(R) A3(R) ! A2(R)
*++++,++++-
ax + by + cz + d = 0
a*x + b*y + c*z + d* = 0
f : X ! Y
X YY X
S ) X #!S p " XS = p + #!S #!f :
#!X ! #!Y f #!f (v) =f (x0 + v) # f (x0)
f (S) = { f (p + s) : s " #!S }
= { f (p + s) # f (p) + f (p) : s " #!S }
= {#!f (s) + f (p) : s " #!S }
= { f (p) +w : w " #!f (#!S ) ) #!Y }.
#!f #!f (#!S ) ) #!Y
f : X ! Y fA, B, C " X
" =##!AC :
##!AB A* = f (A) B* = f (B) C* = f (C)
###!A*C* :
###!A*B* = ",
f
f : An(K) ! Am(K)
f (x) = Fx + b F b
C = A+ "(B # A),
C* = F(A+ "(B # A)) + b
= FA+ b + "(FB # FA)
= (FA+ b) + "(FB + b # FA# b)
= A* + "(B* # A*),
C* # A* = "(B* # A*)
f : X ! YK .= 2
A, B, C " XA*, B*, C*
###!A*C* :
###!A*B* = ##!AC :
##!AB
f (A) = A* f (B) = B* f (C) = C* f
f O " X
#!f (v) = f (O + v) # f (O)
v " #!X #!f#!X ! #!Y
1 # " K v " #!X OO + v O + #v
(O + #v#O) : (O + v#O) = #,
( f (O + #v) # f (O)) : ( f (O + v) # f (O)) = #,
f (O + #v) = f (O) + #( f (O + v) # f (O),
#!f (#v) = f (O + #v) # f (O) = #( f (O + v) # f (O)) = ##!f (v).
v, w " #!X O + 2v O + v + w O + 2wX 2
((O + 2w) # (O + 2v)) : ((O + v+ w) # (O + 2v)) = 2
,- O + 2w = (O + 2v) + 2((O + v+ w) # (O + 2v)).
f (O + 2w) # f (O + 2v) = 2 ( f (O + v+ w) # f (O + 2v)) ,
,- f (O + 2w) # f (O) # ( f (O + 2v) # f (O))
= 2 ( f (O + v+ w) # f (O) # ( f (O + 2v) # f (O))) ,
,- #!f (2w) # #!f (2v) = 2#!f (v+ w) # 2#!f (2v)
,- 2#!f (v+ w) = #!f (2v) + #!f (2w) = 2#!f (v) + 2#!f (w)
,- #!f (v+ w) = #!f (v) + #!f (w),
#!f f
d / 2f : Ad(R) ! Ad(R)
f
Ad(K) K .= R
K = R
$ : K ! K
z $! z C
K = C f : A2(K) ! A2(K)
f (x, y) = (x, y).
A = (a1, a2) B = (b1, b2) C = (c1, c2)
det
$%%%%%%%&b1 # a1 c2 # a1
b2 # a2 c2 # a2
'((((((() = 0,
fL : C2 ! C2 f (x0 + v) # f (x0)
L(v1, v2) = (v1, v2)
C
L(i, 0) = (#i, 0) .= (i, 0) = iL(1, 0) = L(i, 0).
S, T ) XX #!S ) #!T #!T ) #!S S 0 T
S T S 1 T .= 2
S ) X T ) XS 1 T .= 2 S ) T T ) S
P " S 1 T S T dim(S) 3dim(T) V ) W V W S T
x " S x # P " V x # P " W x " TS ) T
S ) X T ) Xdim(S) = dim(T) S 1 T .= 2 S = T
V = WS = T
#!S = #!T #!S ) #!TS T
A3(R)
A4(R)
S ) X x " XX T ) X dim(S)
x S
T * T xS
x " T 1 T *
X = A2(R)
S, T ) X
S, T ) X XS 1 T X
dim(S) + dim(T) 3 dim(X) + dim (S 1 T)
dim(#!S + #!T ) = dim(
#!X )
x0 " S 1 T
S = x0 +#!S
T = x0 +#!T
S 1 T = x0 +#!S 1 #!T ,
S 1 T ####!S 1 T = #!S 1 #!T
dim(#!S ) + dim(
#!T ) = dim(#!S + #!T ) + dim(
#!S 1 #!T ),
dim(S) + dim(T) = dim(#!S + #!T ) + dim(S 1 T)
3 dim(X) + dim(S 1 T),
dim(#!S + #!T ) 3 dim(
#!X ) = dim(X)
S, T ) X X #!S + #!T =#!X S 1 T
xS xT S T x " XS 1 T v " #!S w " #!T
x = xS + v = xT +w,
v " #!S w " #!T
xT # xS = v #w.
#!S + #!T = #!X xT # xS "#!X s " #!S t " #!T
xT # xS = s + t.
v = s " #!S w = #t " #!T v w
S ) X S .= XW ) #!X #!S +W =
#!XX S W pS,W : X ! S
x " XT = Tx,W x W S 1 Tx,W
#!S + ###!Tx,W =#!S +W =
#!Xdim(S 1 Tx,W ) = 0
S W pS,W
4x " X, pS,W (x) " S 1 Tx,W .
rS,W : X ! XS W ) #!X #!S +W = #!X
rS,W (x) = pS,W (x) +########!xpS,W (x)
r2 = r 5 r = 1X SS
f =pS,W S X W#!X #!S x " S
f (x) = x x " X L :#!X ! #!S
L(v) = f (x + v) # f (x) v {pS,W (x + v)} =S 1 Tx+v,W {pS,W (x)} = S 1 Tx,W Tx,W Tx+v,W
W x x + vx " S f (x) = x #!X = #!S +Wv " #!X v = s + w s " #!S w " W w " W
y " X W yy +w
y +W = y +w +W ,
Tx+v,W = Tx+s+w,W = Tx+s,W ,
f (x + v) = f (x + s) x " S s " #!S x + s " Sf (x + s) = x + s
f (x + v) # f (x) = f (x + s) # f (x) = x + s # x = s,
L(v) = s L :#!X = #!S +W ! #!S
r = rS,W
X ! X
r(x) = p(x) +####!xp(x) = p(x) + (p(x) # x)
p x " XL(v) = r(x + v) # r(x)
L(v) = p(x + v) + (p(x + v) # (x + v)) # (p(x) + (p(x) # x))
= p(x + v) # p(x) + (p(x + v) # p(x) # (x + v) + x)
= 2(p(x + v) # p(x)) # v,
v p(x + v) # p(x)v
K = R K = C
V %= Kn
X #!X %= Kn
x0 " X X#!X ! X
v $! x0 + v.
x0
Kn
0
A3(K) x, y, z (#, %,#1)(#, %,#1) z = 0 (x, y, z)
*+++++++,+++++++-
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
#
%
#1
'(((((((((((((()
: t " K
.+++++++/+++++++0
z = 0
p :
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()$!
$%%%%%%%&x + #zy + %z
'((((((() =
$%%%%%%%&1 0 #
0 1 %
'((((((()
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((().
A4(K) x, y, z, ww = 0 (a, b, c,#1)
A3(K) x, y, z w = 0 z = 0(#, %,#1)
*++++++++++,++++++++++-
$%%%%%%%%%%%%%%%%%%%%%%&
xyzw
'(((((((((((((((((((((()
+ t
$%%%%%%%%%%%%%%%%%%%%%%&
abc#1
'(((((((((((((((((((((()
: t " K
.++++++++++/++++++++++0
1{w = 0}
$%%%%%%%%%%%%%%%%%%%%%%&
xyzw
'(((((((((((((((((((((()
$!
$%%%%%%%%%%%%%%&
x + awy + bwz + cw
'(((((((((((((()=
$%%%%%%%%%%%%%%&
1 0 0 a0 1 0 b0 0 1 c
'(((((((((((((()
$%%%%%%%&1 0 #
0 1 %
'((((((()
$%%%%%%%%%%%%%%&
1 0 0 a0 1 0 b0 0 1 c
'(((((((((((((()=
$%%%%%%%&1 0 # a + #c0 1 % b + %c
'((((((()
A4(K)
z = w = 0 (a, b, c,#1)(#, %,#1, 0) (x, y, z, w) X, Y , Z , W
*+++++++++++++++++++++,+++++++++++++++++++++-
X = x + sa + t#
Y = y + sb + t%
Z = z + sc # t
W = w # s
W = 0
Z = 0
*++++++++++++,++++++++++++-
X = x + sa + t#
Y = y + sb + t%
s = w
t = z + sc
,-
*++++++++++++,++++++++++++-
X = x +wa + (z +wc)#
Y = y +wb + (z +wc)%
s = w
t = z +wc
X = x + #z + (a + #c)w
Y = y + %z + (b + %c)w.
A B
C D
E F
G H
I J
K L
M N
O P
AEMI BFNJ CGOK DHPL ACKI BDLJ EGOM FHPN ACGEBDHF IKOM JLPN ABJI CDLK EFNM GHPO ABFE CDHG IJNM KLPOABDC EFHG IJLK MNPO
p1 p2 Xp = !1 p1 + !2 p2
!1 + !2 = 1 K = R
!1 = !2 = 1/2p1 p2
##!p1p = ##!pp2
p1 p2
!1 / 0 !2 / 0 !1 + !2 = 1p = !1p1 + !2 p2.
[0, 1] ) R
S ) X = An(R)
W #!S #!X #!S +W =#!X p
S W r SW x " X p(x)
x r(x)
r SS x " S r(x) = x
A3(R) A2(R)$%%%%%%%%%%%%%%&
000
'(((((((((((((()$!
$%%%%%%%&01
'((((((()
$%%%%%%%%%%%%%%&
100
'(((((((((((((()$!
$%%%%%%%&10
'((((((()
$%%%%%%%%%%%%%%&
010
'(((((((((((((()$!
$%%%%%%%&11
'((((((()
$%%%%%%%%%%%%%%&
111
'(((((((((((((()$!
$%%%%%%%&00
'((((((()
A2(R) ! A2(R)
x = y
A3(R)$%%%%%%%%%%%%%%&
100
'(((((((((((((()
$%%%%%%%%%%%%%%&
1/21/20
'(((((((((((((()
$%%%%%%%%%%%%%%&
1/31/31/3
'(((((((((((((()
A4(R)
A4 3
A4(C)
r$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()= t
$%%%%%%%%%%%%%%&
111
'(((((((((((((()
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()= t
$%%%%%%%%%%%%%%&
100
'(((((((((((((()
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()=
$%%%%%%%%%%%%%%&
010
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
001
'(((((((((((((()
A3(R)$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()=
$%%%%%%%%%%%%%%&
110
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
001
'(((((((((((((()
A4(R)
x1, x2, x3, x4
*++++,++++-
x1 # x3 = 1
x2 # x4 = 1
$%%%%%%%%%%%%%%%%%%%%%%&
x1
x2
x3
x4
'(((((((((((((((((((((()
=
$%%%%%%%%%%%%%%%%%%%%%%&
1100
'(((((((((((((((((((((()
+ u
$%%%%%%%%%%%%%%%%%%%%%%&
1111
'(((((((((((((((((((((()
+ v
$%%%%%%%%%%%%%%%%%%%%%%&
1001
'(((((((((((((((((((((()
.
k A3(R)$%%%%%%%%%%%%%%&
21k
'(((((((((((((()
$%%%%%%%%%%%%%%&
1k0
'(((((((((((((()
$%%%%%%%%%%%%%%&
110
'(((((((((((((()
X f : X ! XABC
A*B*C* ##!AC :##!AB =
###!A*C* :
###!A*B*
ABC
GA(n, R) X = An(R) A " An(R)
A GA(n, R) A XGA(n, R) X ( X
f (A, B) = ( f (A), f (B)) f " GA(n, R) (A, B) " X2
(A, B) " X2 (A, B)GA(n, R) X ( X ( X
f (A, B, C) = ( f A, f B, f C) f " GA(n, R) A, B, C " X(A, B, C) " X3
(A, B, C)
A3(R) ! A2(R)
A3(R) r1
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()=
$%%%%%%%%%%%%%%&
100
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
010
'(((((((((((((()
r2
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()=
$%%%%%%%%%%%%%%&
010
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
001
'(((((((((((((()
r3
$%%%%%%%%%%%%%%&
xyz
'(((((((((((((()=
$%%%%%%%%%%%%%%&
001
'(((((((((((((()+ t
$%%%%%%%%%%%%%%&
100
'(((((((((((((()
A : A3(R) ! A3(R) A(r1) = r2 A(r2) =
r3 A(r3) = r1
f : X ! Y T ) YY f #1(T) X
A, B KP A B
##!AP :##!AB + ##!BP :
##!BA = 1
(##!AP :
##!AB) · (##!AB :##!AP) = 1
##!PA :##!PB = #
##!AP :##!AB
##!BP :##!BA
A, B, C Q(!0, !1, !2) A, B, C
Q = !0A+ !1B + !2C,
!0 + !1 + !2 = 1 Q .= A !1 + !2 .= 0Q* = 1
!1 + !2(!1B + !2C) BC QA
!1 + !2 = 0
A B CK PAB PBC PCA AB BC
CA A B CAPBC BPCA CPAB
####!APAB####!PABB
####!BPBC####!PBCC
####!CPCA####!PCAA
= 1
A B CK PAB PBC PCA
AB BC CA A B CPAB PBC PCA
####!APAB####!PABB
####!BPBC####!PBCC
####!CPCA####!PCAA
= #1.
$ : R ! R
x, y " R $(xy) = $(x)$(y) $(x + y) = $(x) + $(y)
k " Z $(k) = k
q " Q $(q) = q
x < y $(x) < $(y) t = y # x0 < $(
6t)2 = $(t)
$ R ! R
x " R $(x) = x $ 1R
X %= A2(K) K f : X !X
A B C X rA + x##!AB ##!AC s A + y##!AC##!AB r s A+ x##!AB + y##!AC " X
D = A + ##!AB + ##!AC (x, y) " K2 t A + x##!ADD A+ y##!AB t
AB A+ xy##!AB
f X Xf
f : X ! X
f (A) = A* f (B) = B* f (C) = C* A*B*C*
X A*B*C*
f g : X ! Xf (A) = A* = A f (B) = B* = B f (C) = C* = C
#!f : K2 ! K2 #!f (v) = f (A + v) # f (A)#!f (v+ w) = #!f (v) + #!f (w)
$ & f (A + x##!AB) = A + $(x)##!AB f (A +y##!AC) = A+ &(y)##!AC #!f (x, y) = ($(x),&(y))
OD $(x) = &(x) x " K$ : K ! K
(x, y) " K2 $(xy) = $(x)$(y) $(x + y) = $(x) + $(y)
K = R $(x) $(x) = x
f : Ad(R) ! Ad(R)