(I) Here, the quantifier is ‘there exists’.
The invalidation of this assertion is as per the following
There doesn’t exists a number which is equivalent to its square
(ii) Here, the quantifier is ‘for each’.
The nullification of this assertion is as per the following
There exist a genuine number\[x\], with the end goal that x isn’t not exactly \[x\text{ }+\text{ }1\]