If x ∝ 1/y then :
x = 1/y
y = 1/x
xy = 1
xy = non-zero constant
y is a non zero constant else 1y should not be indeterminate.
Since x is inversely proportional to y, x is also a non zero constant.
If x≠ y then, (x,y)≠(y,x)And, (x,y)=(y,x), if x=y.