.
2.1. < x, y > x y, .
< x, y > < u, v> , x = u y = v.
2.1.
< a, b >, <1, 2>, < x, 4> .
, , n - < x 1, x 2, xn >.
2.2. ( ) A B , , A, B:
A ´ B = {< a, b >, ç a Î b Ï }.
n 1, 2, n 1 ´ 2 ´ ´ n, < a 1, a 2, , an > n, , i- ai i, ai Î i.
2.2.
= {1, 2}, = {2, 3}.
A ´ B = {<1, 2>, <1, 3>,<2, 2>,<2, 3>}.
2.3.
= { x ç0 £ x £ 1} B = { y ç2 £ y £ 3}
A ´ B = {< x, y >, ç0 £ x £ 12 £ y £ 3}.
, A ´ B , , x = 0 ( ), x = 1, y = 2 y = 3.
. .
2.3. ( ) r .
< x, y > r, : < x, y > Î r , , xr y.
2.4.
r = {<1, 1>, <1, 2>, <2, 3>}
n - n -.
, , (. . 1.1). .
2.5.
1. r = {<1, 2>, <2, 1>, <2, 3>} ;
2. r = {< x, y > ç x + y = 7, x, y } x + y = 7.
, . = { a 1, a 2, , an } . C n, cij :
cij =
2.6.
= {1, 2, 3, 4}. r .
1. r = {<1, 2>, <1, 3>, <1, 4>, <2, 3>, <2, 4>, <3, 4>} .
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2. r = {< ai, aj > ç ai < aj; ai, aj Î } "" .
3. C.
2.7.
.
1. .
) £ <1, 2>, <5, 5>, <4, 3>;
) " , " <3, 6>, <7, 42>, <21, 15>, <3, 28>.
2. .
) " (0, 0)" (3, 4) (2, Ö21), (1, 2) (5, 3);
) " OY " (x, y) ( x, y).
3. .
) " ";
) " ";
) " ".
2.4. r Dr = {x ç y, xr y}.
2.5. r Rr = {y ç x, xr y}.
2.6. r Mr = Dr ÈRr.
, :
r Î Dr ´ Rr
Dr = Rr = A, , r A.
2.8.
r = {<1, 3>, <3, 3>, <4, 2>}.
Dr = {1, 3, 4}, Rr = {3, 2}, Mr = {1, 2, 3, 4}.
, .
2.9.
r 1 = {<1, 2>, <2, 3>, <3, 4>}.
r 2 = {<1, 2>, <1, 3>, <2, 4>}.
r 1 È r 2 = {<1, 2>, <1, 3>, <2, 3>, <2, 4>, <3, 4>}.
r 1 Ç r 2 = {<1, 2>}.
r 1 \ r 2 = {<2, 3>, <3, 4>}.
2.10.
R . :
r 1 " £ "; r 2 " = "; r 3 " < "; r 4 " ³ "; r 5 " > ".
r 1 = r 2 È r 3;
r 2 = r 1 Ç r 4;
r 3 = r 1 \ r 2;
r 1 = ;
.
2.7. r ( r 1),
r 1 = {< x, y > ç< y, x > Î r }.
2.11.
r = {<1, 2>, <2, 3>, <3, 4>}.
r 1= {<2, 1>, <3, 2>, <4, 3>}.
2.12.
r = {< x, y > ç x y = 2, x, y Î R }.
r 1 = {< x, y > ç< y, x > Î r } = r 1 = {< x, y > ç y x = 2, x, y Î R } = {< x, y > ç x + y = 2, x, y Î R }.
2.8. r s
s r = {< x, z > ç y, < x, y > Î r < y, z > Î s }.
2.13.
r = {< x, y > ç y = sinx }.
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s = {< x, y > ç y = Ö x }.
s r = {< x, z > ç y, < x, y > Î r < y, z > Î s } = {< x, z > ç y, y = sinx z = Ö y } = {< x, z > ç z = Ö sinx }.
:
y = f (x), z = g (y) Þ z = g (f (x)).
2.14.
r = {<1, 1>, <1, 2>, <1, 3>, <3, 1>}.
s = {<1, 2>, <1, 3>, <2, 2>, <3, 2>, <3, 3>}.
s r , x, y, z. < x, y > Î r < y, z > Î s (. 2.1).
2.1
< x, y > Î r | < y, z > Î s | < x, z > Î s r |
<1, 1> <1, 1> <1, 2> <1, 3> <1, 3> <3, 1> <3, 1> | <1, 2> <1, 3> <2, 2> <3, 2> <3, 3> <1, 2> <1, 3> | <1, 2> <1, 3> <1, 2> <1, 2> <1, 3> <3, 2> <3, 3> |
, , , . :
s r = {<1, 2>, <1, 3>, <3, 2>, <3, 3>}.
2.9. r X, x Î X xr x.
, < x, x > Î r.
2.15.
) X , X = {1, 2, 3} r = {<1, 1>, <1, 2>, <2, 2>, <3, 1>, <3, 3>}. r . X , .
.
) X r . , .. .
) X r " ". , .. .
2.10. r X, x, y Î X xry yr x.
, r , r = r 1.
2.16.
) X , X = {1, 2, 3} r = {<1, 1>, <1, 2>, <1, 3>, <2, 1>, <3, 1>, <3, 3>}. r . X , .
.
) X r . , .. x y, y x.
) X r " ". , .. x y, y x.
2.11. r X, x, y, z Î X xry yr z xr z.
xry, yr z, xr z , < x, z > r r. r , r r r, . . r r Í r.
2.17.
) X , X = {1, 2, 3} r = {<1, 1>, <1, 2>, <2, 3>, <1, 3>}. r , . . < x, y > < y, z > < x, z >. , <1, 2>, <2, 3> <1, 3>.
) X r £ ( ). , .. x £ y y £ z, x £ z.
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) X r " ". , .. x y y z, x z.
2.12. r X, , X.
2.18.
) X , X = {1, 2, 3} r = {<1, 1>, <2, 2>, <3, 3>}. r .
) X r . .
) X r " ". .
r X.
2.13. r X x Î X. , x, X, y Î X, xry. , x, [ x ].
, [ x ] = { y Î X | xry }.
X, . . , X.
2.19.
) : x [ x ] = { x }, .. .
) , < x, y > :
[< x, y >] = .
, < x, y >, .
) .
2.14. r X, x, y Î X xry yr x x = y.
, , < x, y > r r 1, x = y. , r Ç r 1 < x, x >.
2.20.
) X , X = {1, 2, 3} r = {<1, 1>, <1, 2>, <1, 3>, <2, 2>, <2, 3>, <3, 3>}. r .
s = {<1, 1>, <1, 2>, <1, 3>, <2, 1>, <2, 3>, <3, 3>} . , <1, 2> Î s, <2, 1> Î s, 1 ¹2.
) X r £ ( ). , .. x £ y, y £ x, x = y.
2.15. r ( ) X, , X. X £, .
, , , .
2.21.
) X , X = {1, 2, 3} r = {<1, 1>, <1, 2>, <1, 3>, <2, 2>, <2, 3>, <3, 3>}. r .
) Í U .
) .
.
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y x, x y = f (x). x , y . x ( y), . , .
.
2.16. , .
.
2.22.
) {<1, 2>, <3, 4>, <4, 4>, <5, 6>} .
) {< x, y >: x, y Î R, y = x 2} .
) {<1, 2>, <1, 4>, <4, 4>, <5, 6>} , .
2.17. f , Df , Rf f.
2.23.
2.22 ) Df {1, 3, 4, 5}; Rf {2, 4, 6}.
2.22 ) Df = Rf = (¥, ¥).
x Df y Rf. y = f (x). x y f, y f x x f.
, , .
2.18. Df = X Rf = Y, , f X Y, f X Y (X Y).
2.19. f g , D, x Î D f (x) = g (x).
( , . . ): f g , , .
2.20. () f , y Y x Î X, , y = f (x).
, f () Df Rf.
f , X Y , ³ .
2.21. () f , f (a) = f (b) a = b.
2.22. () f , .
f , X Y , = .
2.23. Df , f -.
2.24.
) f (x) = x 2 . .. f ( a) = f (a), a ¹ a, .
) x R = ( , ) f (x) = 5 -. R {5}. , .
) f (x) = 2 x + 1 , .. 2 x 1 +1 = 2 x 2 +1 x 1 = x 2.
2.24. , X 1 ´ X 2 ´...´ Xn Y n- .
2.25.
) , , R , . . R 2 R.
) f (x, y) = , R ´ (R \ ) R. , .. f (1, 2) = f (2, 4).
) , N 2 (N ) .
, . , f f 1 .
2.26.
) f = {<1, 2>, <2, 3>, <3, 4>, <4, 2>} .
f 1 = {<2, 1>, <3, 2>, <4, 3>, <2, 4>} .
) g = {<1, a >, <2, b >, <3, c >, <4, D >} .
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g -1 = {< a, 1>, < b, 2>, < c, 3>, < D, 4>} .
) f ) g -1 ). g -1 f = {< a, 2>, < b, 3>, < c, 4>, < d, 2>}.
fg -1 = Æ.
, (g -1 f )(a) = f (g -1(a)) = f (1) = 2; (g -1 f )(c) = f (g -1(c)) = f (3) = 4.
f, , :
1) - , ..
a 0 + a 1 x +... + anxn
b 0 + b 1 x +... + bmxm.
2) f (x) = xm, m .
3) f (x) = ex.
4) f (x) = logax, a >0, a 1.
5) sin, cos, tg, ctg, sec, csc.
6) sh, ch, th, cth.
7) arcsin, arccos ..
, log 2(x 3 + sincos 3 x) , .. cosx, sinx, x 3, x 1 + x 2, logx, x 2.
, , .
, . . . . 1957 . 13- :
. n .
1. (. 2.2):
2.2
x | x 1 | x 2 | ... | xn |
f (x) | f (x 1) | f (x 2) | ... | f (xn) |
2.27.
. k , p (k) , k , k = 1, 2,..., 6.
p (k) (. 2.3):
2.3
k | ||||||
p (k) | 1/6 | 1/6 | 1/6 | 1/6 | 1/6 | 1/6 |
, , .
, (, ), , , , .., .
2. , . .
2.28.
f (x) = sin (x + Ö x) :
g (y) = Ö y; h (u, v) = u + v; w (z) = sinz.
3. . , , . . f (n), n = 1, 2,... : ) f (1) ( f (0)); ) f (n + 1) f (n) . n!: ) 0! = 1; ) (n + 1)! = n!(n + 1). .
4. , , . :
fM (x) =
fM (x) M.
, , f X Y, .. X ´ Y, . , , : , , . , , .
2.29.
,
Fn = Fn- 1 + Fn- 2 (n ³ 2) (2.1)
F 0 = 1, F 1 = 1.
(2.1) :
n | 0 1 2 3 4 5 6 7 8 9 10 11 |
Fn | 1 1 2 3 5 8 13 21 34 55 89 144 |
, .
2
1. .
2. ?
3. r r = r 1?
4. r r r Í r.
5. .
6. .
7. ?
) .
) .
3.
, 1736 . . , , . , . , , . , , , .