问题
填空题
命题“∃x∈R使x2+2x+1<0”的否定是______.
答案
∵命题“∃x∈R使x2+2x+1<0”是特称命题
∴否定命题为:∀x∈R,使x2+2x+1≥0
故答案为:∀x∈R,使x2+2x+1≥0.
命题“∃x∈R使x2+2x+1<0”的否定是______.
∵命题“∃x∈R使x2+2x+1<0”是特称命题
∴否定命题为:∀x∈R,使x2+2x+1≥0
故答案为:∀x∈R,使x2+2x+1≥0.