Answer
a) 1
b) 0
c) 1
d) 0
Work Step by Step
Before starting the problem, consider the domain of all the integers.
a) $\forall n(n^2\geq 0)$ is true, because the square of any negative integer $m$ is $m^2=(-1)^2l^2=l^2$, where $l$ is a positive integer.
b) The statement that $\exists n(n^2=2)$ is untrue, because $\sqrt{2}$ is not an integer.
c) $\forall n(n^2\geq n)$ is true.
d) $\exists n(n^2<0)$ is not true, because there are no imaginary integers.
