Identity element - Jamb Mathematics Past Questions and Answers

Question 1:

• JAMB 2017

If m * n = [mn − nm] for m, n belong to R, evaluate − 3 * 4

A. 3
B. 4
C. 5
D. 6

Question 2:

• JAMB 2019

A binary operation \(\otimes\) is defined by \(m \otimes n = mn + m - n\) on the set of real numbers, for all m, n \(\in\) R. Find the value of 3 \(\otimes\) (2 \(\otimes\) 4).

A. 6
B. 25
C. 15
D. 18

Question 3:

• JAMB 2014

A binary operation * is defined by x * y = x^y. If x * 2 = 12 - x, find the possible values of x

A. 3,4
B. 3,-4
C. -3,4
D. -3,-4

Question 4:

• JAMB 1992

If the binary operation \(\ast\) is defined by m \(\ast\) n = mn + m + n for any real number m and n, find the identity of the elements under this operation

A. E = 1
B. E = -1
C. E = -2
D. E = 0

Question 5:

• JAMB 1998

The identity element with respect to the multiplication shown in the diagram below is \(\begin{array}{c|c} \otimes & p & p & r & s \\ \hline p & r & p & r & p
\\ q & p & q & r & s\\ r & r & r & r & r\\ s & q & s & r & q\end{array}\)

A. P
B. Q
C. R
D. S