Factorise by applying the Factor Theorem
P(x)=3x^3-4x^2-7x-2
Factor Theorem
2009-11-12 1:00 am
回答 (2)
2009-11-12 4:31 am
✔ 最佳答案
P(x) = 3x^3 - 4x^2 - 7x - 2Try in turns x = +/-1, +/-2, +/-1/3 and +/-2/3
P(-2/3) = 3(-2/3)^3 - 4(-2/3)^2 - 7(-2/3) - 2
= -8/9 - 16/9 + 42/9 - 18/9
= 0
So (3x + 2) is a factor
By long division, (3x^3 - 4x^2 - 7x - 2)/(3x + 2) = x^2 - 2x - 1
So P(x) = 3x^3 - 4x^2 - 7x - 2 = (3x + 2)(x^2 - 2x - 1)
2009-11-23 7:09 pm
收錄日期: 2021-04-13 16:56:10
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https://hk.answers.yahoo.com/question/index?qid=20091111000051KK00947