The function rule of the reciprocal function is obtained algebraically by writing the rule for the pairings shown in the table above.
The reciprocal function is a member of a larger family of functions used to model inverse variations. These functions have the general form where both the constant and the variable are nonzero. For this reason, the reciprocal function is also known as the inverse variation parent function.
It is important not to confuse the reciprocal of a function with the inverse of a function. For numbers, refers to the reciprocal while the notation is commonly used to refer to the inverse of a function.