VOL 1: d y/ d x is the notation used for the derivative of y with respect to x, for example on Carestian x, y, coordinate system where y is the vertical axis and x is the horizontal axis.example: when you sit up right on the toilet you sit in a vertical position (y) and your feet are aligned in a horizontal position (x), and when you push the shit out your ass, you asshole and your shit exert an equal and opposite force with one anotherWhere F=MA in physics this law states that force equals mass times acceleration, you exert a FORCE when you shit, and that force is proportional to the mass of your [EXPLETIVE] and the acceleration of which the shit falls out your ass.In this case the acceleration is 9.8m/s squared, which is the acceleration due to gravity, not to be confused with velocity which is the derivative of acceleration, or speed which is the 3rd derivative of acceleration.Now thats some shitty mathematics.