3
x y. A 2x+2y d"
2
x - y d" 0 A B
{-1, 1, 0, 2} x y
|x - y| = 1
X
1 - |x| dla x "< -1, 1 > .
f(x) =
0 w p.p.
(X, Y )
X Y
X Y
P (XY < 0)
3
)
4
(Nt : t e" 0)  = 2 P (Nt = 1, N4t = 3, N5t = 3)
(X, Y )
cx2y dla y e" 0 '" x2 + y2 d" 1
f(x, y) =
0 w p.p
c
X Y
X Y
{1, 2, 3, 4} Xn = k k
n
(Xn : n e" 1)
{X2 = 2, X3 = 3}