x3-x2-3x-1化简

Question

x3-x2-3x-1 化简

Answer 1

已经是最简式了,除非你搞反了,应该是因式分解.下面按因式分解
x³-x²-3x-1
=x³+x²-2x²-2x-x-1
=x²(x+1)-2x(x+1)-(x+1)
=(x+1)(x²-2x-1) /如果你还没学实数范围内分解,到此结束,实数范围,继续：
=(x+1)(x²-2x+1-2)
=(x+1)[(x-1)²-2]
=(x+1)(x-1+√2)(x-1-√2)