English

Let * be the binary operation defined on Q. Find which of the following binary operations are commutative a * b = (a – b)2 ∀ a, b ∈ Q - Mathematics

Advertisements
Advertisements

Question

Let * be the binary operation defined on Q. Find which of the following binary operations are commutative

a * b = (a – b)2 ∀ a, b ∈ Q

Sum
Advertisements

Solution

Given that * is a binary operation defined on Q.

a * b = (a – b)2, ∀ a, b ∈Q

b * a = (b –a)2

Since, (a – b)2 = (b – a)2

Thus, * is commutative.

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Relations And Functions - Exercise [Page 13]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 12
Chapter 1 Relations And Functions
Exercise | Q 26. (iv) | Page 13

RELATED QUESTIONS

Determine whether or not of the definition of given below gives a binary operation. In the event that * is not a binary operation, give justification for this.

On Z+, define * by ab


Determine whether or not each of the definition of given below gives a binary operation. In the event that * is not a binary operation, give justification for this.

On R, define * by ab2


For each binary operation * defined below, determine whether * is commutative or associative.

On Z, define − b


Define a binary operation *on the set {0, 1, 2, 3, 4, 5} as

a * b = `{(a+b, "if a+b < 6"), (a + b - 6, if a +b >= 6):}`

Show that zero is the identity for this operation and each element a ≠ 0 of the set is invertible with 6 − a being the inverse of a.


Number of binary operations on the set {ab} are

(A) 10

(B) 16

(C) 20

(D) 8


If a * b denotes the larger of 'a' and 'b' and if a∘b = (a * b) + 3, then write the value of (5) ∘ (10), where * and ∘ are binary operations.


Determine whether the following operation define a binary operation on the given set or not : 'O' on Z defined by a O b = ab for all a, b ∈ Z.


Determine whether the following operation define a binary operation on the given set or not : '*' on N defined by a * b = a + b - 2 for all a, b ∈ N


Check the commutativity and associativity of the following binary operation  '*' on Z defined by a * b = a + b − ab for all a, b ∈ Z ?


Show that the binary operation * on Z defined by a * b = 3a + 7b is not commutative ?


On the set Q of all ration numbers if a binary operation * is defined by \[a * b = \frac{ab}{5}\] , prove that * is associative on Q.


Let * be a binary operation on Z defined by
a * b = a + b − 4 for all a, b ∈ Z Show that '*' is both commutative and associative ?


Let * be a binary operation on Z defined by
a * b = a + b − 4 for all a, b ∈ Z Find the invertible elements in Z ?


Let * be a binary operation on Q − {−1} defined by a * b = a + b + ab for all a, b ∈ Q − {−1} Show that '*' is both commutative and associative on Q − {−1}.


Let 'o' be a binary operation on the set Q0 of all non-zero rational numbers defined by \[a o b = \frac{ab}{2}, \text{ for all a, b } \in Q_0\] :

 Find the identity element in Q0.


Let 'o' be a binary operation on the set Q0 of all non-zero rational numbers defined by  \[a o b = \frac{ab}{2}, \text{ for all a, b } \in Q_0\]:

Find the invertible elements of Q0 ?


Let R0 denote the set of all non-zero real numbers and let A = R0 × R0. If '*' is a binary operation on A defined by

(a, b) * (c, d) = (ac, bd) for all (a, b), (c, d) ∈ A

Find the identity element in A ?


Construct the composition table for ×6 on set S = {0, 1, 2, 3, 4, 5}.


For the binary operation ×10 on set S = {1, 3, 7, 9}, find the inverse of 3.


For the binary operation ×7 on the set S = {1, 2, 3, 4, 5, 6}, compute 3−1 ×7 4.


Consider the binary operation 'o' defined by the following tables on set S = {a, bcd}.

o  a b c d
a a a a a
b a b c d
c a c d b
d a d b c

Show that the binary operation is commutative and associative. Write down the identities and list the inverse of elements.


Write the total number of binary operations on a set consisting of two elements.


A binary operation * is defined on the set R of all real numbers by the rule \[a * b = \sqrt{  a^2 + b^2} \text{for all a, b } \in R .\]

Write the identity element for * on R.


Let * be a binary operation defined by a * b = 3a + 4b − 2. Find 4 * 5.


Let * be a binary operation defined on set Q − {1} by the rule a * b = a + b − ab. Then, the identify element for * is ____________ .


Which of the following is true ?


Let * be a binary operation on R defined by a * b = ab + 1. Then, * is _________________ .


For the binary operation * defined on R − {1} by the rule a * b = a + b + ab for all a, b ∈ R − {1}, the inverse of a is ________________ .


On the set Q+ of all positive rational numbers a binary operation * is defined by \[a * b = \frac{ab}{2} \text{ for all, a, b }\in Q^+\]. The inverse of 8 is _________ .


Determine whether * is a binary operation on the sets-given below.

a * b = min (a, b) on A = {1, 2, 3, 4, 5}


Define an operation * on Q as follows: a * b = `(("a" + "b")/2)`; a, b ∈ Q. Examine the existence of identity and the existence of inverse for the operation * on Q.


Fill in the following table so that the binary operation * on A = {a, b, c} is commutative.

* a b c
a b    
b c b a
c a   c

Let A = `((1, 0, 1, 0),(0, 1, 0, 1),(1, 0, 0, 1))`, B = `((0, 1, 0, 1),(1, 0, 1, 0),(1, 0, 0, 1))`, C = `((1, 1, 0, 1),(0, 1, 1, 0),(1, 1, 1, 1))` be any three boolean matrices of the same type. Find (A v B) ∧ C


Let N be the set of natural numbers. Then, the binary operation * in N defined as a * b = a + b, ∀ a, b ∈ N has identity element.


The identity element for the binary operation * defined on Q ~ {0} as a * b = `"ab"/2` ∀ a, b ∈ Q ~ {0} is ______.


Let A = N x N and * be the binary operation on A defined by (a, b) * (c, d) = (a + c, b + d). Then * is ____________.


Find the identity element in the set I+ of all positive integers defined by a * b = a + b for all a, b ∈ I+.


The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is ____________.


Let * be a binary operation on the set of integers I, defined by a * b = a + b – 3, then find the value of 3 * 4.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×