当m取何值时,不论x取何值分式(x-1)/(-2x²+12x-18+m)总有意义

问题描述:

当m取何值时,不论x取何值分式(x-1)/(-2x²+12x-18+m)总有意义

(-2x²+12x-18+m)
=-2(x²-6x+9)+m
= -2(x-3)²+m
∵-2(x-3)²∴要使总有意义
只需要-2(x-3)²+m∴m