Determine whether or not each definition * given below gives a binary operation. In the event that * is not a binary operation give justification of this.

On Z + , defined * by a*b = ab


Here, Z + denotes the set of all non – negative integers.

Given that ‘*’ is an operation that is valid in the Positive integers ‘Z + ’ and it is defined as given:


a*b = ab, where a,bZ + ,


Since aZ + and bZ + ,


According to the problem it is given that on applying the operation ‘*’ for two given positive integers it gives a Positive integer as a result of the operation,


a*bZ + – ...... (1)


We know that p q>0 if p>0 and q>0.


ab>0N


abZ +


The operation * defines a binary operation on Z +.


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