(a) 因式分解 x^3 - 64
答案 : ( x - 4 )( x^2 + 4x + 16 )
(b) 由此 , 因式分解 x^3 - 28x + 48
答案 : ( x - 4 )( x - 2 )( x - 6 )
請清楚寫明步驟，因為我不明白 ... 尤其是(b)不明白 ...
請幫幫忙 !!!
感激不盡，謝謝 !!!
因式分解_中二數學一條
2011-04-26 1:06 am
回答 (3)
2011-04-26 1:20 am
2011-04-26 1:22 am
(a) 有2條式
x^3-y^3=(x-y)(x^2+xy+y^2)
x^3+y^3=(x+y)(x^2-xy+y^2 )
x^3 - 64
= (x)^3 - (4)^3
= (x - 4) (x^2 + 4x + 16)
(b)
x^3 - 28x + 48
=x^3 + 0x^2 - 28x + 48 (要加0x^2 先可以除到x - 4)
= (x - 4) (x^2 + 4x - 12)
= (x - 4) (x - 2) (x - 6)
希望幫到你
x^3-y^3=(x-y)(x^2+xy+y^2)
x^3+y^3=(x+y)(x^2-xy+y^2 )
x^3 - 64
= (x)^3 - (4)^3
= (x - 4) (x^2 + 4x + 16)
(b)
x^3 - 28x + 48
=x^3 + 0x^2 - 28x + 48 (要加0x^2 先可以除到x - 4)
= (x - 4) (x^2 + 4x - 12)
= (x - 4) (x - 2) (x - 6)
希望幫到你
參考: me
2011-04-26 1:12 am
(a) x^3 - 64
=x^3 - 4^3
=( x - 4 )( x^2 + 4x + 16 )
=x^3 - 4^3
=( x - 4 )( x^2 + 4x + 16 )
收錄日期: 2021-04-23 20:44:16
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https://hk.answers.yahoo.com/question/index?qid=20110425000051KK00953