week of November 2, 2009

This week in science class i learned about graphing and describing data and writing functions.

I learned these ideas by:

Drawing trend lines to explain the graph. A trend line points to the general direction that the points are going to. They don't need to be exactly on the points but they have to have an arrow at the end.

Writing Functions. To make a function you write the dependent variable and put the independent variable in parenthesis next to it. Then you multiply the physical quantity number by the two units and then by the variable.

Using variables as numbers we don't know. This is hard to explain but it is like using a letter in place or a number that we don't know, like in algebra. For example, the starting time of a jogger could be t1 and the ending could be t2.

Coming up with variable expressions. For example, if you want to find out how long the jogger ran for you would have to do t1-t2. It is hard to figure out these expressions when the questions and situations become more complicated.

It is important to know these ideas so you can make graphs if you are a salesperson or you are trying to convince someone to do something. KNowing this stuff will help you express your data once it is collected, so you can display it in a way that is easy to understand and work with. It is good to find patterns in your data so you can make predictions about what will happen (like people do when choosing stocks). It helps to know the independent and dependent variable in your data.