Re: [中學] 多項式求值
※ 引述《Intercome (今天的我小帥)》之銘言：
: 若a、b屬於有理數，x = a+b√2，使得f(x) = x^4 + 4x^3 + 4x^2 + 4x + 3 = 4√2
: 求 a+b =?
(x^4+4x^3+4x^2+4x+3)^2 - 32
=(x^2+2*x-1)*(x^6+6*x^5+13*x^4+20*x^3+27*x^2+22*x+23)
x = -1 + √2 (YES)
= -1 - √2 (NO)
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◆ From: 27.147.57.77
推
07/28 22:08, , 1F
07/28 22:08, 1F
23 is prime
it is not difficult
※ 編輯: JohnMash 來自: 27.147.57.77 (07/29 09:32)
推
07/29 16:06, , 2F
07/29 16:06, 2F
→
07/29 17:45, , 3F
07/29 17:45, 3F
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