Практикум по алгебре. Часть 1. Многочлены и их корни. Попов В.В - 14 стр.

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f
1
(x) = x
3
+ ax + b, f
2
(x) = x
4
+ cx
3
+ d,
f
3
(x) = x
2
+ 1, f
4
(x) = x
2
+ ex.
a, b, c, d e f
i
(x)
f
j
(x) i, j = 1, 2, 3, 4
f
1
(x) = (x 1)
2
(x + 1)
3
(x 3)(x 4), f
2
(x) = (x
2
1)
4
,
f
3
(x) = (x
3
1)(x
2
2x + 1)
2
, f
4
(x) = 2x
3
3x
2
+ 5x + 4,
f
5
(x) = (x + 1)(x 1)
5
(x 4)
2
(x + 2).
f(x) g(x)
a) f(x) = x
4
+ x
3
+ 2x
2
+ x + 1, g(x) = x
3
2x
2
+ x 2;
b) f(x) = x
4
+ 2x
3
+ 2x
2
+ 2x + 2, g(x) = x
3
+ 3x
2
;
c) f(x) = x
4
+ x
3
3x
2
x 1, g(x) = x
3
+ x
2
x 1;
d) f(x) = x
5
+ x
4
x
3
2x 1, g(x) = 3x
4
+ 2x
3
+ x
2
+ 2x 2.
f(x) g(x)
f(x) g(x)
a) x
4
+ 5x
3
+ 4x
2
+ x + 4 x
3
+ 3x
2
3x + 4 x + 4
b) x
4
2x
3
2x
2
+ 2x + 4 x
3
3x 2 x 2
c) x
4
+ 5x
3
+ 4x
2
5x 2 x
3
+ 6x
2
+ 9x + 2 x + 2
d) x
5
2x
4
x
2
3x 1 x
4
2x
3
x
2
x
2
2x 1
e) x
5
6x
3
+ 8x
2
+ x + 10 x
4
3x
3
+ 2x
2
+ x + 2 x 2
f) x
5
+ x
3
+ x
2
+ x 1 x
4
+ x
3
+ x
2
+ x + 1 x + 1
      Çàäà÷è.

      4.1. Äàíû ìíîãî÷ëåíû
            f1 (x) = x3 + ax + b,    f2 (x) = x4 + cx3 + d,
                 f3 (x) = x2 + 1, f4 (x) = x2 + ex.
Ïðè êàêèõ çíà÷åíèÿõ ïàðàìåòðîâ a, b, c, d è e ìíîãî÷ëåí fi (x)
äåëèòñÿ íà ìíîãî÷ëåí fj (x), ãäå i, j = 1, 2, 3, 4?
    4.2. Çàäàíû ìíîãî÷ëåíû
 f1 (x) = (x − 1)2 (x + 1)3 (x − 3)(x − 4), f2 (x) = (x2 − 1)4 ,
 f3 (x) = (x3 − 1)(x2 − 2x + 1)2 ,          f4 (x) = 2x3 − 3x2 + 5x + 4,
 f5 (x) = (x + 1)(x − 1)5 (x − 4)2 (x + 2).
Íàéòè:
   a) ÍÎÄ êàæäîé ïàðû ìíîãî÷ëåíîâ;
   b) ÍÎÄ êàæäîé òðîéêè ìíîãî÷ëåíîâ;
   c) ÍÎÄ âñåõ ìíîãî÷ëåíîâ;
   d) ÍÎÊ êàæäîé ïàðû ìíîãî÷ëåíîâ.
   4.3. Íàéòè ÍÎÄ ìíîãî÷ëåíîâ f (x) è g(x) ñ ïîìîùüþ àëãî-
ðèòìà Åâêëèäà:
 a) f (x) = x4 + x3 + 2x2 + x + 1,       g(x) = x3 − 2x2 + x − 2;
 b) f (x) = x4 + 2x3 + 2x2 + 2x + 2,     g(x) = x3 + 3x2 ;
 c) f (x) = x4 + x3 − 3x2 − x − 1,       g(x) = x3 + x2 − x − 1;
 d) f (x) = x5 + x4 − x3 − 2x − 1,       g(x) = 3x4 + 2x3 + x2 + 2x − 2.
      4.4. Ñ ïîìîùüþ àëãîðèòìà Åâêëèäà íàéäè ÍÎÄ ìíîãî÷ëå-
íîâ f (x) è g(x). Íàéòè òàêæå ÍÎÊ ýòèõ ìíîãî÷ëåíîâ.

       f (x)                     g(x)                         Îòâåò: ÍÎÄ
 a)    x4 + 5x3 + 4x2 + x + 4    x3 + 3x2 − 3x + 4            x+4
 b)    x4 − 2x3 − 2x2 + 2x + 4   x3 − 3x − 2                  x−2
 c)    x4 + 5x3 + 4x2 − 5x − 2   x3 + 6x2 + 9x + 2            x+2
 d)    x5 − 2x4 − x2 − 3x − 1    x4 − 2x3 − x2                x2 − 2x − 1
 e)    x5 − 6x3 + 8x2 + x + 10   x4 − 3x3 + 2x2 + x + 2       x−2
 f)    x5 + x3 + x2 + x − 1      x4 + x3 + x 2 + x + 1        x+1

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