设全集为R,则命题a∈(1,5)的否定为a∈______.

问题描述:

设全集为R,则命题a∈(1,5)的否定为a∈______.

设全集为R,则命题a∈(1,5)的否定为a∈(+∞,1]∪[5,+∞)

(负无穷,1]∪[5,正无穷)

a∈(-∞,1]∪[5,+∞)