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-- Mathematics - Section B1
Relations and Functions
Let \(*\) be binary operation on non-zero rational number \(Q^+\) defined by \(a*b=\frac{ab}{2}\) for all \(a,b\in Q^+\) then identity element is
1
2
0
3
for identity element $e$
\(a*e=\frac{ae}{2}=a\)
$⇒ae=2a$
so $e=2$
