Coordinate systems: 
They are two mutually perpendicular coordinate lines which intersect in the origin O on each line.

The four quadrants in a coordinate system:
Quadrant I is the area where a>0 and b>0.
Quadrant II is the area where a<0 and b>0.
Quadrant III is the area where a<0 and b<0.
Quadrant IV is the area where a>0 and b<0.

Distance: 
The distance between any two points is defined as:
.

Data sets:
The grouping or collection of similar or related data.

Subsets:
If A and B are sets and every element of A is also an element of B, then: A is a subset of B, denoted by.

Product of two data sets:
If S and T are sets, the product set of S and T will be denoted by , which satisfies

.

Line:

A geometric figure formed by a point moving along a fixed direction and the reverse direction.

 Slope of a line:
If and are arbitrary two points on the line, the slope can be calculated by
.

Midpoint of any two points:
The distance between two arbitrary points is given by
.

Flash Movie	Flash Game	Flash Card
Core Concept Tutorial	Problem Solving Drill	Review Cheat Sheet

The graphical representation of data and the basic graphs that are generated as a result of this data are important concepts that are developed in this tutorial. The coordinate systems in two variables are introduced with the help of graphs.

The midpoint, and the distance of between two points formulas are discussed in this tutorial with the help of examples and graphical representations. Relations are introduced with the help of graphs and common algebraic principles.

Specific Tutorial Features:
• Step by step examples showing data sets, product of two data sets and relations are shown in this tutorial.
• Examples displaying how to use the distance and midpoint between any two points formulas are presented with the use of graphs and examples.

Series Features:
• Concept map showing inter-connections of new concepts in this tutorial and those previously introduced.
• Definition slides introduce terms as they are needed.
• Visual representation of concepts
• Animated examples—worked out step by step
• A concise summary is given at the conclusion of the tutorial.

Two Dimensional Coordinate Systems
          Coordinate Systems and their Definition
          The Four Quadrants and their Graphical Representation
The Distance and Midpoint Formulas
Relations
          Data sets and their definition
          Subsets 
          The product of two data sets
          The relation of two data sets
Line in a plane
          Definition of a line
          Definition of the slope of a line
          Parallel and perpendicular lines