Manipal MET2012MathematicsMathematical Induction
In the set Q⁺ of all positive rational numbers, the operation * is defined by the formula a * b= a b 6 . Then, the inverse of 9 with respect to * is
Options
- A4
- B3
- C1 9
- D1 3
Correct answer
A. 4
Step-by-step solution
Let e be the identity, array lrl & a^* e & =a & a e 6 & =a & e & =6 & a^* a⁻¹ & =e & a^* a⁻¹ & =6 & a a⁻¹ 6 =6 & a⁻¹= 6 6 a & 9⁻¹= 6 6 9 =4 array