Tuesday, March 10, 2015

determine the reminder of P/Q if P = x^2002 + 2x^2000 - 5x^5 -10x^2 + 2 and Q = (x-1)*x^2 .

We'll write the rule of division with
reminder:


P(x)=Q(x)*C(x)+R(x), where the degree of the
polynomial


R(x)<the degree of the polynomialQ(x).
Because the degree of Q(x) is 3, so the degree of  R(x) is
2.


R(x)=ax^2+bx+c


We'll
calculate the root of Q(x):


(x-1)*x^2 =
0


We'll set each factor as
0:


x-1 = 0


x1 =
1


x^2 = 0


x2=x3 =
0


 The roots of Q(x) are: x1=1,
x2=x3=0.


If we'll substitute x=1 in P(x), we'll
obtain:


P(1)= 1+2-5-10+2


But
P(x)=Q(x)*C(x)+R(x), P(1)=0*C(x)
+a+b+c=a+b+c


a+b+c=-10
(1)


P(0) =
c


P(0)=2


c=2


If
x=0 is a multiple root, this one has to verify the first derivative
,too.


P'(0) =
0


P'(x)=2002x^2001+4000x^1999-25x^4-20x=-2a+b


-2a+b
= 0 (2)


But from (1) and
c=2=>a+b+c=-10=>a+b+2= -10=>a+b=-12
(3)


We'll subtract (2) from
(3):


a+b+2a-b = -12-0


We'll
eliminate like terms:


3a =
-12


We'll divide by
3:


a =
4


We'lll substitute a=4 in
(2):


-2*4+b =
0


b =
8


R(x)=4x^2+8x+2

No comments:

Post a Comment

Comment on the setting and character of &quot;The Fall of the House of Usher.&quot;How does setting act as a character?

Excellent observation, as it identifies how the settings of Poe's stories reflect the characters of their protagonists. Whet...