方程X^2-2X-2=0根是X=1加减根号3,则X^2-2x-2可分解为( )
问题描述:
方程X^2-2X-2=0根是X=1加减根号3,则X^2-2x-2可分解为( )
答
[ x - (1+√3)][ x - (1-√3)]
= x^2 - [ 1+√3+(1-√3)]x + (1+√3)(1-√3)
= x^2 - 2x + (1^2 - 3)
= x^2 - 2x - 2