Leo A. Aroian, The Probability Function of the Product of Two Normally Distributed Variables, The Annals of Mathematical Statistics, Vol. 18, No. 2 (Jun., 1947), pp. 265-271 ...

This is called function notation and is just another way of expressing the relationship between two variables. Therefore, in general y = f (x).

Educational Studies in Mathematics, Vol. 95, No. 2 (June 2017), pp. 181-202 (22 pages) Recent research suggests that children in elementary grades have some facility with variable and variable ...