數學題(保證勁難)1
WITHOUT DIRECT DIVISION, find the reminder of x¹ºº ÷ (x + 1)².
回答 (4)
餘式定理,
(x + 1)²=0
x=-1
reminder=f(-1) 設f(x)=x¹ºº
= (-1)¹ºº
=1
Let f(x)=x^100
Let consider the reminder of f(x)/(x+1)
Sub x=-1 into f(x)
f(-1)=1
The reminder of f(x)/(x+1) is 1.
f(x)-1=x^100-1=(x^99-x^98+x^97-.....+x-1)(x+1)
Let g(x)=(x^100-1)/(x+1)
sub x=-1, g(x)=-1-1-1-1...-1-1=-100
(x+1) is a factor of g(x)+100
h(x)=[g(x)+100](x+1)=(x^100-1)+100(x+1)
h(x) can be divided by (x+1)^2
Expanding h(x)
x^100-1+100x+100=x^100+100x+99
That tell us that we need to add 100x+99 to x^100 , then it can be divided by (x+1)^2
Implied the reminder is -100x-99
Let x be 0,
The equation is:
0¹ºº ÷ (0² + 2x0 +3)
= 0 ÷ 3
= 0
收錄日期: 2021-04-12 21:47:02
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