Let ∗ be the binary operation on N given by a∗b=LCM of a and b.
(i) Find the identity of ∗ in N
The binary operation ∗ on N is defined as a∗b=LCM of a and b.
It is known that
LCM of a and 1 =a =LCM of 1 and a, a∈N.
a∗1=a=1∗a,a∈N
Thus, 1 is the identity of ∗ in N.