Suppose x^2+1 is multiplied by x-x^2+7x^5-2x^3+3x^4+6 and the product is subtracted from x^5-x^4-3x^2+7x+1. Find , in the final result,
a)the coefficient of x^4;
b)the constant term.
Formulae and Polynomials
2007-06-19 8:53 pm
回答 (3)
2007-06-19 9:13 pm
✔ 最佳答案
拿... 你要ge 只係x^4... 所以係唔使理其他數字...只要搵到可以乘出x^4 的 組合..
x^2 X -x^2 =-x^4
+1 X 3x^4 =3x^4
---------------------------
=2x^4 ( <---就係x^2+1 乘 x-x^2+7x^5-2x^3+3x^4+6 的Product 中的x^4)
..........................
Subtraced from x^5-x^4-3x^2+7x+1
我的理解係.... (x^5-x^4-3x^2+7x+1)- Product = final result..
a) Coefficient of x^4 = -1 - 2
=-3
b)Constant term = -5
+1-(1X6)=-5
2007-06-19 9:20 pm
豬油包﹐your answer is wrong
2007-06-19 9:06 pm
(x^2+1)(x-x^2+7x^5-2x^3+3x^4+6) - (x^5-x^4-3x^2+7x+1)
= (x^2+1)(6+x-x^2-2x^3+3x^4+7x^5) - (x^5-x^4-3x^2+7x+1)
a)
coefficient of x^4 = (1)(-1) + (1)(3) + 1 = 3
b)
constant term = 6 - 1 = 5
唔係好難,自己對應下,睇下邊件乘邊件會得 x^4 咪計到 a), 同理 b) 都唔難
= (x^2+1)(6+x-x^2-2x^3+3x^4+7x^5) - (x^5-x^4-3x^2+7x+1)
a)
coefficient of x^4 = (1)(-1) + (1)(3) + 1 = 3
b)
constant term = 6 - 1 = 5
唔係好難,自己對應下,睇下邊件乘邊件會得 x^4 咪計到 a), 同理 b) 都唔難
收錄日期: 2021-04-12 19:58:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070619000051KK01628