Show that addition, subtraction and multiplication are binary operations on R, but division is not a binary operation on R. Further, show that division is a binary operation on the set R. of non-zero real numbers.
+ : R x R → R is given by (a, b) → a + b – : R x R → R is given by
(a,b) → a – b
x : R x R → R is given by (a, b) → a b
Since ‘+’, ‘–‘ and ‘x’ are functions, they are binary operations on R.
But ÷ : R x R → R, given by is not a function and hence not a binary operation, as for
is not defined.
However, ÷ : R* x R* → R*, given by is a function and hence a binary operation on R*.