(a) 展開( x - 2 / 3 )^3 。
(b)在( 2x^2 + x - 3 )( x - 2 / 3 )^3 的展式中,求x的係數。
A . Maths
2008-07-05 7:15 am
回答 (2)
2008-07-05 7:44 am
✔ 最佳答案
(a) x^3 - (3C1)(2/3)x^2 + (3C2)[(2/3)^2] x - (3C3)(2/3)^3
= x^3 - 2x^2 + 4x/3 - 8/27
(b)
(2x^2 + x - 3) (x - 2/3)^3
= (2x^2 + x - 3) (x^3 - 2x^2 + 4x/3 - 8/27)
Consider the terms of x^1
(-3)(4x/3) - (8/27)x
= -4x - 8x/27
= -116x/27
x的係數 = -116/27
2008-07-05 8:13 am
收錄日期: 2021-04-24 09:48:38
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https://hk.answers.yahoo.com/question/index?qid=20080704000051KK02958