Question
The identity element for the binary
operation * defined on $Q - \{ 0\}$ as $a*b =
\frac{{ab}}{2},\forall a,b \in Q - \{ 0\}$ is
- (a) 1
- (b) 0
- (c) 2 ✓ Correct
- (d) None of these
Relations and Functions — Class 12 Maths Solution
Step-by-step Solution
It is given that,, $a*b = \frac{{ab}}{2},\forall a,b \in Q - \{ 0\}$.
Let $e$ be the identity element for *.
$\therefore$ $a*e = \frac{{ae}}{2}$
$\Rightarrow$ $a = \frac{{ae}}{2} \Rightarrow e = 2$
NCERT & Exemplar solution for CBSE Class 12 Mathematics, Relations and Functions. Curated by Sachin Sharma. Free for all students.