Mathematics is a universal science that underlies the development of modern technology and has an important role invarious disciplines. Mathematics plays an important role in alldimensions of life. Learning mathematics is to learn to think inlogical, analytical, systematic, critical and creative.

Mathematics is not difficult. Hard is relative. If you do not know it, you do not love it. For me, for friends, for students, for parents or anyone who is interested, let us learn together.

Monday, March 21, 2011

V. SET TYPES (continuation)

4. The Part set (or subset), namely the set whose members are part of another set member.
For example:
D = {0, 1, 2, 3, 4, 5, 6, 7} and
E = {3, 2, 6, 7}, it appears here that every element E is also a member of the set D.

It says H is "subset" of C and E ⊂ K be written.
"Subset" is denoted by ⊂.
Or say also set D "contains the set of" E and is written D ⊃ E. "Contains a set" is denoted by ⊃.
The set E is a subset of D if each member / element E is also a member of D. And because each member of E is contained in D, then E is said also contained in D.

How many subsets of a set?

From the set K = {2, 3, 5} we can form subsets: {}, {2}, {3}, {5}, {2, 3}, {2, 5}, {3, 5} and {2, 3, 5}.
Subsets obtained by 8 = 23 (2 to the 3rd), 3 is the number of elements of K.

Thus the number of subsets of the set which has n element is 2n (two raised to the n th power).

Note: The empty set (null set) is a subset of all kinds of sets.
5. The Same set, namely two sets of all its members together.
For example:
If K = {a, b, c, d} and L = {b, d, a}, then is said to set K = set of L and is written K = L.
Note: The order of the members in each set not to be the same.

K and L is said to equal if every element of K is an element of L and vice versa

every element of L is an element of K as well.

6. The Universe set or the Universal set or Universum, namely a set that contains all objects that are being discussed.
The objects that being discussed had established a set of the Universe.

The Universe set is represented by "U" (from Universum / Universal). On the set of Venn diagrams, the Universe set depicted with rectangular.
Example:
             If A = {0, 2, 4, 6}, then set A is probably derived from
U = {integers}
U = {whole numbers}
U = {even numbers less than 8} or the set of another universe

containing 0, 2, 4, and 6.
Obviously when we talk about a set, of course this set is a subset of a specific universe set.