All Junior Cert Mathematics posts
• #### Help with sets Katrina.khod

Hello, I do not understand sets at all. Can somebody please explain or give notes to me.

Thanks so much

Happy new year

1. #### K1234

A set is a well defined collection of objects e.g. The set of whole numbers between 1and 5 is a well defined set but the set of good actors is not. Different people will give different answers.

Two sets are equal is they contain the exact same elements.

2. #### K1234

If E= { the first five letters in the alphabet} then:

d is an element of E but y is not an element of E.

The set from which all others are being considered is called the universal set, U.

If every element of set E is also an element of set F then E is said to be a subset of F.

The union of two sets is found by putting together in a new set all the elements of E and F without repeating an element.

The intersection of two sets E and F is the set of elements found in both E and F.

The complement of set E is the set of elements in the universal set U which are not in E. It is written as E'.

The book of formulae and tables has some set symbols.

3. #### Katrina.khod

Thank you so much

It helped a lot

k