MATHEMATICS I (MATEMATİK I) - (İNGİLİZCE) Dersi Sets and Numbers soru detayı:

CEVAP:

A set A is called finite if it consists of a finite number of elements. Otherwise it is called an
infinite set.The set A = {1 ,3, 5} is finite, whereas the set B = {1, 3, 5, 7, …} is infinite.
For a finite set A, the number of elements in this set is denoted by s(A). For A = {1, 3, 5} we have s(A) = 3. The following equality is true:
s(A ? B) = s(A) + s(B) –s(A ? B)