हिंदी

For the Binary Operation ×7 on the Set S = {1, 2, 3, 4, 5, 6}, Compute 3−1 ×7 4. - Mathematics

Advertisements
Advertisements

प्रश्न

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

योग
Advertisements

उत्तर

Finding identity element:
Here,

1 \[\times_7\] 1 = Remainder obtained by dividing 1\[\times\] 1 by 7
           = 1

3 \[\times_7\] 4 = Remainder obtained by dividing 3 \[\times\] 4 by 7
           = 5 

4  \[\times_7\] = Remainder obtained by dividing 4 \[\times\] 5 by 7
           = 6 

So, the composition table is as follows:

×7  1 2 3 4 5 6
1 1 2 3 4 5 6
2 2 4 6 1 3 5
3 3 6 2 5 1 4
4 4 1 5 2 6 3
5 5 3 1 6 4 2
6 6 5 4 3 2 1

We observe that all the elements of the first row of the composition table are same as the top-most row.
So, the identity element is 1. 

\[3 \times_7 5 = 1\]= 5 

So, 3-1 = 5

Now,

\[ 3^{- 1} \times_7 4 = 5 \times_7 4 = 6\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Binary Operations - Exercise 3.5 [पृष्ठ ३३]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 12
अध्याय 3 Binary Operations
Exercise 3.5 | Q 6 | पृष्ठ ३३

संबंधित प्रश्न

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 a ∗ b = a – b


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

On Z+, define ab


Consider the binary operations*: ×→ and o: R × R → defined as a * b = |a - b| and ab = a, &mnForE;ab ∈ R. Show that * is commutative but not associative, o is associative but not commutative. Further, show that &mnForE;abc ∈ Ra*(b o c) = (ab) o (a * c). [If it is so, we say that the operation * distributes over the operation o]. Does o distribute over *? Justify your answer.


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

On R, define * by a * b = a + 4b2

Here, Z+ denotes the set of all non-negative integers.


The binary operation * : R × R → R is defined as a * b = 2a + b. Find (2 * 3) * 4.


Check the commutativity and associativity of the following binary operation  '*' on R defined by a * b = a + b − 7 for all ab ∈ R ?


Check the commutativity and associativity of the following binary operation'*' on Q defined by a * b = (a − b)2 for all ab ∈ Q ?


Check the commutativity and associativity of the following binary operation '*' on N defined by a * b = gcd(a, b) for all a, b ∈ N ?


The binary operation * is defined by \[a * b = \frac{ab}{7}\] on the set Q of all rational numbers. Show that * is associative.


On Q, the set of all rational numbers a binary operation * is defined by \[a * b = \frac{a + b}{2}\] Show that * is not associative on Q.


Let S be the set of all rational numbers except 1 and * be defined on S by a * b = a + b \[-\] ab, for all a, b \[\in\] S:

Prove that * is a binary operation on S ?


Let S be the set of all rational numbers except 1 and * be defined on S by a * b = a + b \[-\] ab, for all a, b \[\in\] S:

Prove that * is commutative as well as associative ?


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 Q0 (set of non-zero rational numbers) defined by \[a * b = \frac{ab}{5} \text{for all a, b} \in Q_0\]

 Show that * is commutative as well as associative. Also, find its identity element if it exists.


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

Show that '*' is both commutative and associative on A ?


Let * be the binary operation on N defined by a * b = HCF of a and b.
Does there exist identity for this binary operation one N ?


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 identity element for the binary operation * defined on the set R of all real numbers by the rule

\[a * b = \frac{3ab}{7} \text{ for all a, b} \in R .\] ?


Write the composition table for the binary operation multiplication modulo 10 (×10) on the set S = {2, 4, 6, 8}.


If a binary operation * is defined on the set Z of integers as a * b = 3a − b, then the value of (2 * 3) * 4 is ___________ .


Q+ denote the set of all positive rational numbers. If the binary operation a ⊙ on Q+ is defined as \[a \odot = \frac{ab}{2}\] ,then the inverse of 3 is __________ .


If G is the set of all matrices of the form

\[\begin{bmatrix}x & x \\ x & x\end{bmatrix}, \text{where x } \in R - \left\{ 0 \right\}\] then the identity element with respect to the multiplication of matrices as binary operation, is ______________ .


Q+ is the set of all positive rational numbers with the binary operation * defined by \[a * b = \frac{ab}{2}\] for all ab ∈ Q+. The inverse of an element a ∈ Q+ is ______________ .


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


Consider the binary operation * defined on Q − {1} by the rule
a * b = a + b − ab for all a, b ∈ Q − {1}
The identity element in Q − {1} is _______________ .


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

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


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


Let A = {a + `sqrt(5)`b : a, b ∈ Z}. Check whether the usual multiplication is a binary operation on A


Consider the binary operation * defined on the set A = {a, b, c, d} by the following table:

* a b c d
a a c b d
b d a b c
c c d a a
d d b a c

Is it commutative and associative?


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 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 ∧ B) v C


Choose the correct alternative:

A binary operation on a set S is a function from


Choose the correct alternative:

Which one of the following is a binary operation on N?


Choose the correct alternative:

In the set Q define a ⨀ b = a + b + ab. For what value of y, 3 ⨀ (y ⨀ 5) = 7?


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

a * b = a – b for a, b ∈ Q


Let R be the set of real numbers and * be the binary operation defined on R as a * b = a + b – ab ∀ a, b ∈ R. Then, the identity element with respect to the binary operation * is ______.


Let * be binary operation defined on R by a * b = 1 + ab, ∀ a, b ∈ R. Then the operation * is ______.


Which of the following is not a binary operation on the indicated set?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×