Question

HELP ME PLEASE Given that the universal set is all real numbers, write the complement of set A. Set A: {Irrational numbers}

Answer 1

Answer: The complement is Q, the set of the rational numbers.

Step-by-step explanation:

Ok, here we can use the fact that the set of all the real numbers is equal to the union of the set of the rational numbers and the set of the irrational numbers. (Remember that Q, the rational numbers, also does include the set of the integer numbers))

Then, if the universal set is R, we have that the universal set is:

R = Q + I

Where Q = set of rational numbers and I = set of irrational numbers.

Then, the complement of the set A =  I = irrational numbers, is equal to:

R - I = Q + I - I = Q

Then the set of the rational numbers is the complement of the set A.