Identify the quantifier in the following statements and write the negation of the statements.
(i) There exists a number which is equal to its square.
(ii) For every real number x, x is less than x + 1.
(iii) There exists a capital for every state in India.
Write the negation of the following statement:
'There does not exist a quadrilateral which has all its sides equal'
Find the negation of the statement - 'There exists a rational number x such that its square is 2 '.