According to economists, this episode of great recession was resulted from a sudden busting of house bubble in US, where the house bubble was caused by rapid growth of improper regulation on sub-prime mortgages (Merriam 2009; Wang 2009; Whitney 2007).
When working with equations that have two variables, the coordinate plane is an important tool. It's a way to draw pictures of equations that makes them easier to understand. To create a coordinate plane, start with a sheet of graph or grid paper. Next, draw a horizontal line.
Once a graph is constructed, it will be clear how much, and if, the independent variable influences the other. Not all equations and graphs are two-dimensional. In an experiment with two independent variables, which are usually designated as x and y, the dependent variable is usually z. The z-axis is the third dimension that typically represents depth or height.