问题 选择题 已知命题p:∀x1,x2∈R,(f(x2)-f(x1))(x2-x1)≥0,则¬p是( )A.∃x1,x2∈R,(f(x2)-f(x1))(x2-x1)≤0B.∀x1,x2∈R,(f(x2)-f(x1))(x2-x1)≤0C.∃x1,x2∈R,(f(x2)-f(x1))(x2-x1)<0D.∀x1,x2∈R,(f(x2)-f(x1))(x2-x1)<0 答案 答案:C