Well-defined
Well defined means an object or thing or element that is ”clearly defined” or ”described”, meaning there is no need to describe more.
Well-defined set Example:
- A = {1,3,5,7} here the 1,3,5,7 all are well defined. All have their own value.
This set is consist of the first four odd numbers. That is a well-defined set.
This set is consist of two distinct dishes. This is a well-defined set.
Some Practical Examples of Well defined Set:
If a Teacher says to the student to bring a set of 5 plastic chairs, the student brings plastic chairs instead of a wooden one, because the plastic chair is well defined there is no need to clarify more.
Counter Examples of Well defined Set:
- All the intelligent members of the family.
Here intelligence is not well defined because we can not distinguish between the intelligence of the family members. Each member is intelligent in itself.
- All the tall boys in the Class.
Here the tall boy is not well defined because everyone in the class is different in height so we can not distinguish.
- All the good leaders of the nation.
Here good leaders are not well-defined because we can not distinguish between the good leaders of a nation. Because we don’t really know about the good leader.
Not well-Defined
Not Well defined means an object or thing or element that is ” not clearly defined” meaning there is a need to describe more. If the element of a set is not well defined then it is called an undefined set.
For more knowledge about set in Mathematics click here