Expert: Scott A Wilson - 10/4/2009

Question
what are linear models? how do you know if an equation is a linear model? are all linear models straight lines?

Answer
A linear model is when linear equations are used.

If there are two variable and two unknowns, the result is a line.
In 3-space, the equation all from planes.
In 4-space, the regions all define a 3 space.

In equations like this, they are usually not thought of as dimensions, however.

Yet as long as all of the variables are to the first, it is called a linear set of equations.

With that same number of unique equations as variables, they are solvable.

If some of the equations are inequalites, that is called an operations research problem.

I believe they were first used in WWII when weapons were produced in different areas and
needed to be shipped to different area all over the world.