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.
A trajectory is nothing more than the path an object follows as it moves through space. For this lesson, we are going to concentrate on a ballistic trajectory, which is the path an object follows through space after it is initially launched, with its path dictated only by the laws of motion, gravity and possibly air resistance.