# Week 8 – Math 10

This week in math 10, we learned about Coordinate Planes and what domain and range are.

The domain is the set of all numbers for the independent variables in the relation. The range is the set of all numbers for the dependent variable in the relation.

Both the input and output of a function are variables, which means that they change. you can choose the input variables yourself, but the output variables are always determined by the rule established by the function.

Coordinate planes are divided into four quadrants. By convention they are numbered one to four, the first quadrant being.

You can locate any point on the coordinate plane by a counter-clockwise from there. Also by convention they are often numbered using Roman numbers I (where the signs of the (x;y) coordinates are I (+;+), II (−;+), III (−;−), and IV (+;−) to the top right, and then going ordered pair of numbers ( x, y ) called  the coordinates.

We normally call the horizontal number line the x-axis, and we normally call the vertical number line the y-axis.