The sign: Foamy or bubbly urine. What it means: You could have kidney disease. When your kidneyâs filtering units arenât working properly, that can lead to a build-up of protein in your urine. The protein then creates a foamy appearance when it hits the water in the toilet.
This gives us a point in the x1-x2 or phase plane that we can plot. Doing this for many values of t will then give us a sketch of what the solution will be doing in the phase plane. A sketch of a particular solution in the phase plane is called the trajectory of the solution.
As you remember from pre-algebra a coordinate plane is a two-dimensional number line where the vertical line is called the y-axis and the horizontal is called the x-axis. These lines are perpendicular and intersect at their zero points. This point is called the origin. The axes divide the plane into four quadrants. A point in a coordinate plane is named by its ordered pair of the form of (x, y). The first number corresponds to the x-coordinates and the second to the y-coordinate.