帝京大学diy研究生:帮忙解答一个因式分解题
来源:百度文库 编辑:神马品牌网 时间:2024/10/04 23:49:43
x∧3 +x∧2-2
就是x3+x2-2
就是x3+x2-2
x*x*x+x*x-2
=x*x*x-1+x*x-1
=(x-1)(x*x+x+1)+(x+1)(x-1)
=(x-1)(x*x+2x+2)
解:用拆项法
x3+x2-2=(X^3-1)+(X^2-1)
=(X-1)(X^2+X+1)+(X+1)(X-1)
=(X-1)(X^2+2X+2)
是x*x*x+x*x-2吧?
x*x*x+x*x-2
=x*x*x-1+x*x-1
=(x-1)(x*x+x+1)+(x+1)(x-1)
=(x-1)(x*x+2x+1)
=(x-1)(x+1)^2
云,兄弟们答的真快~~~
符号不明确