Q63 / 180 · COMEDK 2017 · Mathematics
If $*$ be a binary operation on a set $A$ and $e$ be the identity element w.r.t. *, then $b \in A$ is said to be inverse of $a \in A$ w.r.t. * , if
- A$a^{*} e=b^{*} e$
- B$a=b$
- C$a * a=b * b$
- Correct answerD$a * b=b * a=e$
Solution
$b \in A$ is said to be an inverse of a w.r.t. operation $*$ if $a * b=b * a=e$. [by definition]
Hence, the correct answer is option: 'D'.