A parameter, also known as a parametric variable, is a variable. When we study the current problems, we are concerned about the changes of some variables and their relationships. One or several of them are called independent variables, and the other or several are called dependent variables. If we introduce one or some other variables to describe the changes of independent variables and dependent variables, then the introduced variables are not the variables that must be studied in the current problem, so we call such variables parametric variables or parameters.

Parameter is an option that can be used in many mechanical settings or maintenance. Literally, it is data for reference, but sometimes it is not all data. It can be a given constant value for a given application. Generally speaking, it can be a variable to control other variables that change with it. In short, the parameters are for our reference.

The parametric equation of a circle x=a+r cosθ y=b+r sinθ (a, b) The parametric equation x=a cosθ y=b sinθ a is the long semi-axis length b is the short semi-axis length θ is the parametric hyperbolic equation x=a secθ (secθ). Y=b tanθ a is the real half-axis length b is the imaginary half-axis length θ is the parameter parabola equation X = X = 2pt 2Y = 2pt p is the focus and the distance T from the directrix is the parameter straight line equation x=x'+tcosa y=y'+tsina, X', Y' and A are the straight lines passing through (X', Y'), the inclination angle is A, and T is the parameter.