c =
6
π
2
F
ξ,η
(x, y) =
1
π
2
arctan
x
2
+
π
2
arctan
y
3
+
π
3
F
ξ
(x) =
1
π
arctan
x
2
+
π
2
F
η
(y) =
1
π
arctan
y
3
+
π
2
1
2
F
ξ,η
(x, y) =
sin x+sin y−sin (x+y)
2
x, y ∈
0,
π
2
1+sin y−cos y
2
x >
π
2
y ∈
0,
π
2
1+sin x−cos x
2
y >
π
2
x ∈
0,
π
2
1 x, y >
π
2
0 x, y < 0 F
ξ
(x) =
1+sin x−cos x
2
0 6 x 6
π
2
1 x >
π
2
0 x < 0; F
η
(y) =
1+sin y−cos y
2
0 6 y 6
π
2
1 y >
π
2
0 y < 0
P
(ξ >
π
4
, η <
π
2
) =
1
2
c = 1/2 f
ξ,η
(x, y) = cos x cos y x, y ∈
0,
π
2
x 6∈
0,
π
2
y 6∈
0,
π
2
1
2
f
ξ,η
(x, y) = 2
−x
3
−y
ln 2 ln 3
x > 0, y > 0, 0 x < 0 y < 0
41
54
p = 1
f
ξ,η
(x, y) =
1
4
x ∈ [2, 4], y ∈ [3, 5] 0 x 6∈ [2, 4]
y 6∈ [3, 5] F
ξ,η
(x, y) =
1
4
(x − 2)(y − 3) x ∈ [2, 4], y ∈ [3, 5]
1
2
(x−2) x ∈ [2, 4], y > 5,
1
2
(y −3) x > 4, y ∈ [3, 5] 1
x > 4, y > 5 0 x < 0 y < 0.
M
ξ =
2
3
R;
D
ξ =
R
2
18
P
{ξ = −1} = 0, 2
P
{ξ = 0} = 0, 35
P
{ξ = 1} = 0, 45
P
{η = 1} = 0, 8
P
{η = −1} = 0, 2
M
ξ
1
=
M
ξ
2
= 0;
D
ξ
1
=
D
ξ
2
= 1/2; cov(ξ
1
, ξ
2
) = 0
sign(a) −1 0
|ξ| >
1
2
, ξ
2
>
1
4
−
1
5
α
2
−β
2
α
2
+β
2
0
0 (σ
1
− σ
2
)
2
6
D
(ξ
1
+ ξ
2
) 6 (σ
1
+ σ
2
)
2
φ(ξ) =
1
2
ξ +
1
4
; a =
1
2
; b =
1
4
;
1
8
φ(ξ) = −
1
3
ξ; a =
−
1
3
; b = 0;
1
√
24
c =
1
√
2−1
; a = −0, 1133 . . . ; 0, 047 . . .
P
{η = −1} = F
ξ
(0−),
P
{η = 0} = F
ξ
(0) − F
ξ
(0−)