Let's take as example a linear function of the form:
y = kx.
Where,
k is the constant of proportionality.
Therefore, the proportionality constant is the point:
(x, kx)
Generically it is always the point:
(x, k * f (x))
Where, f (x) is a function proportional to x.
answer:
The constant of proportionality is always the point (x, k * f (x)), where k is the constant of proportionality.
