Thursday, January 8, 2009


Hi every one!

I hope everyone did well on the test. Today we started a new unit called Functions. Function is a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another.

We can express functions in ways such as:-
1. sets:- For example A:{2,3,4,5} and set B:{6,7,8,9}.

2. Graphs:- For example this is a graph of the equation f(x)=x^2+2.

3. Formula:- For example f(x)=x^2+2.

We have also talked about relations. Relation is a set of order pairs.
Types of relation functions

1. One-to-one Relation:- this relation is a function because only one element of set A is corresponding another element in set B.

2. One-to-many Relation:- this is not an a function because the element 1 from set is corresponding to 2,4 in set B.

3. Many-to-one Relation:- 3 elements from set A are corresponding to the element 4 in set B which is many to one.

We have also talked about the vertical line test. It is a vertical line that touches the graph only once.
For example this graph is a Function because it touches the vertical line test once.

This one is not a function because it touches the vertical line test twice.

Sources :-

Next Scribe :- Ale ...


Dr. Eviatar said...

Great job, Nohom! Your scribe post was really clear, with nice figures. Mr. K has very kindly invited me to hang around virtually with you guys - I hope you don't mind ;-).

I was just wondering, why is a curve not a function if a vertical line cuts through it twice?

Cheers, Dr. Eviatar.

Nohom said...

Thank you Dr. Evaitar