Implicit function - Wikipedia
https://en.wikipedia.org/wiki/Implicit_functionan implicit function is a function that is defined by an implicit equation, that relates one of the variables, considered as the value of the function, with the others considered as the arguments. : 204–206 for example, the equation x2 + y2 − 1 = 0 of the unit circle defines y as an implicit function of x if −1 ≤ x ≤ 1, and one restricts y to …