Ask Questions, Get Answers

Want to ask us a question? Click here
Home  >>  TN XII Math
0 votes

If * is a binary operation defined in $Q^+$ as $a*b=\large\frac{ab}{3}$, then the inverse element of 4*6 is ?

$\begin{array}{1 1}\large\frac{9}{8} \\\large\frac{8}{9} \\ \large\frac{2}{3} \\ \large\frac{3}{2}\end{array}$

Can you answer this question?

1 Answer

0 votes
  • If $e\in Q^+$ is the identity element , then $a*e=a \:\:\forall\:a\in\: Q^+$
  • If $a*b=b*a=e$, where e is the identity element of * then b is inverse of a and viceversa.
Let e be the identity element then
$a*e=a\:\Rightarrow \large\frac{ae}{3}=a$
$\Rightarrow e=3$
Let $x$ be the inverse element of 8
Then $ 8*x=3$ $\Rightarrow\:\large\frac{8x}{3}=$$3$


answered May 12, 2013 by rvidyagovindarajan_1

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App