Given that the remainder when dividing a polynomial f(x) by x^4 -1 is 2x^3 -5x +7.
If r(x) is the remainder when f(x) is divided by x^2 -1, find r(-2)
Help with Maths Polynomial Remainder Theorem?
2016-08-14 11:30 am
回答 (1)
2016-08-14 4:19 pm
✔ 最佳答案
f(x)= ( x^4 - 1 )*Q(x) + 2x^3 - 5x + 7
= ( x^2 + 1 )( x^2 - 1 )*Q(x) + ( x^2 - 1 )( 2x ) - 3x + 7
= ( x^2 - 1 )[ ( x^2 + 1 )*Q(x) + 2x ] - 3x + 7
So r(x) = - 3x + 7
r( - 2 ) = - 3( - 2 ) + 7 = 13
Ans: 13
收錄日期: 2021-05-02 14:19:31
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