Question

設(shè)有兩個命題p:關(guān)于x的不等式(x+2)的解集為{x|x≥-2};命題q:若函數(shù)y=kx²-kx-1的值恒小于0,則-4<k<0.則有(   )

A.“p且q”為真命題                    B.“p或q”為真命題

C.“p”為真命題                    D. “q”為假命題

Answer 1

C

解析:由(x+2) x²-3x+2=0或

解得{x|-2≤x≤1或x≥2},故命題p為假命題;

函數(shù)y=kx²-kx-1的值恒小于0,即kx²-kx-1<0恒成立,

當(dāng)k=0時,-1<0恒成立,

當(dāng)k≠0時,需滿足

綜上,若函數(shù)y=kx²-kx-1的值恒小于0,則-4<k≤0,故命題q為假命題.

由真值表知p為真命題.