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.
Perpendicular lines (Coordinate Geometry) When two lines are perpendicular, the slope of one is the negative reciprocal of the other. If the slope of one line is m, the slope of the other is. Try this Drag points C or D. Note the slopes when the lines are at right angles to each other.