R2
A:= {(x, y)R2|x2y22xy 1}
B:= {(x, y)R2|x2+y2+exy 36}
C:= {(x, y)R2|2x2+ 3y2<1}
(E, d) (xn)n0E a E
K={xn|n0}∪{a}E
(E, d) (xn)n0E
a E a
(E, k·k)A B E
A+B:= {a+b|(a, b)A×B}.
A A +B
A B A +B
A B A +B
R×R
A:= {(a, b)R×R|a > 0, ab = 1}B:= {(a, b)R×R|a= 0, b 0}.
A, B A +B
E F R¯
BEE u
E F u(¯
BE)F
x, y E, u(x+y) = u(x) + u(y).
xE r Qu(rx)
M
xE, ku(x)k ≤ Mkxk.
u
(E, k·k)A E a A
ε > 0B(a, ε)A6={a}
f:EE f(A)A
xA\ {a},kf(x)ak<kxak.
f(a) = a
x0A n Nxn+1 =f(xn) (xn)nN
a
n d RnFRn
x0Rn
(fk)kNx0
d(x0, F )+1 d(x0, fk)kNd(x0, F )
d(x0, F )
Rnx7→ d(x, F )U
RnxU d(x, F )
P(x)P:UF
xU(xk)kNUNx
dxk, P (xk)kN
dx, P (x)
d:Rn×RnR Rn×Rn
δ(x1, y1),(x2, y2)= max d(x1, y1), d(x2, y2)
P(xk)kNP(x)
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