The word 'parametric' is used to describe methods in math that introduce an extra, independent variable called a parameter to make them work.
For example, consider the parametric equations of a circle. The circle is defined this way using two equations.
x = r cos(t) and y = r sin(t).
The parameter is t. It is a variable that is not really part of the circle,
but any given value of is t will produce an x and y value pair that lies on the circle radius r.
The parameter is t 'drives' the equation pair to cause them to produce valid coordinate pairs.
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