Практикум по алгебре. Часть 2. Линейные пространства. Попов В.В - 19 стр.

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2x
1
+ x
2
4x
3
= 0,
3
x
1
+ 5
x
2
7
x
3
= 0
,
4x
1
5x
2
6x
3
= 0;
2x
1
x
2
+ 5x
3
+ 7x
4
= 0,
4
x
1
2
x
2
+ 7
x
3
+ 5
x
4
= 0
,
2x
1
x
2
+ x
3
5x
4
= 0;
½
5x
1
+ 3x
2
+ 4x
3
= 0,
6x
1
+ 5x
2
+ 6x
3
= 0;
½
4x
1
6x
2
+ 5x
3
= 0,
6x
1
9x
2
+ 10x
3
= 0;
x
1
+ x
2
+ ··· + x
n
= 0.
L
e
1
e
2
. . . e
n
x L x
1
x
2
. . .
x
n
x = x
1
e
1
+ x
2
e
2
+ . . . x
n
e
n
x
1
x
2
. . . x
n
x
e
1
e
2
. . . e
n
x = (6, 0, 5)
R
3
(3, 0, 0) (0, 2, 0) (0, 0, 1)
(1, 1, 0) (1, 2, 3) (0, 1, 1)
     øåíèé ñëåäóþùèõ óðàâíåíèé:
                                  
          2x1 + x2 − 4x3 = 0,      2x1 − x2 + 5x3 + 7x4 = 0,
      a)   3x1 + 5x2 − 7x3 = 0, c)   4x1 − 2x2 + 7x3 + 5x4 = 0,
                                  
           4x1 − 5x2 − 6x3 = 0;      2x1 − x2 + x3 − 5x4 = 0;
            ½                                ½
                5x1 + 3x2 + 4x3 = 0,             4x1 − 6x2 + 5x3 = 0,
       b)                            d)
                6x1 + 5x2 + 6x3 = 0;             6x1 − 9x2 + 10x3 = 0;

                         e) x1 + x2 + · · · + xn = 0.


6 Ðàçëîæåíèå âåêòîðà ïî áàçèñó. Êîîðäèíàòû
  âåêòîðà â áàçèñå
Ïóñòü â íåêîòîðîì âåêòîðíîì ïðîñòðàíñòâå L çàôèêñèðîâàí áà-
çèñ e1 , e2 , . . ., en . Åñëè x ∈ L, òî íàéäóòñÿ ñêàëÿðû x1 , x2 , . . .,
xn , äëÿ êîòîðûõ x = x1 e1 + x2 e2 + . . . xn en . Óïîðÿäî÷åííûé íà-
áîð x1 , x2 , . . ., xn íàçûâàåòñÿ íàáîðîì êîîðäèíàò âåêòîðà x â
áàçèñå e1 , e2 , . . ., en .
Ïðåäëîæåíèå 11. Êîîðäèíàòû âåêòîðà â çàäàííîì áàçèñå îïðå-
äåëåíû åäèíñòâåííûì îáðàçîì.
Ïðåäëîæåíèå 12. Ïðè ñëîæåíèè âåêòîðîâ ñîîòâåòñòâóþ-
ùèå êîîðäèíàòû ñëàãàåìûõ ñêëàäûâàþòñÿ. Ïðè óìíîæåíèè âåê-
òîðà íà ñêàëÿð åãî êîîðäèíàòû óìíîæàþòñÿ íà ýòîò ñêàëÿð.


   Çàäà÷è.
  1. Íàéäèòå êîîðäèíàòû âåêòîðà x = (6, 0, −5) ïðîñòðàíñòâà
     R3 â áàçèñàõ:
       a) (3, 0, 0), (0, 2, 0), (0, 0, 1);
       b) (1, −1, 0), (1, 2, 3), (0, 1, −1).

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