# Math Help - binary operation

1. ## binary operation

how do i tell if the following equations define a binary operation on Z?

a) m*n=(m+n)/2
b) m*n=mn^2
c) m*n=2^(mn)
d) m*n=sqrt(mn)

2. Originally Posted by mandy123
how do i tell if the following equations define a binary operation on Z?

a) m*n=(m+n)/2
b) m*n=mn^2
c) m*n=2^(mn)
d) m*n=sqrt(mn)
Which of these produces integers?