Ask Questions, Get Answers
Menu
X
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
5 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
studyplans
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
5 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
mobile
exams
ask
sample papers
teach
pricing
sign-in
Download our FREE mobile app with 1000+ tests for CBSE, JEE MAIN, NEET
X
Search
Topics
Want to ask us a question?
Click here
Browse Questions
Student Questions
Ad
Home
>>
CBSE XII
>>
Math
>>
Relations and Functions
+1
vote
let * be a binaray operation on N given by a*b = 1cm (a,b) ,a,b belong to N find 2*4 and is N,* associative?
Share
asked
Oct 4, 2013
by
sharon.r.varghese_1
Please
log in
or
register
to add a comment.
Can you answer this question?
Do not ask me again to answer questions
Please
log in
or
register
to answer this question.
1 Answer
0
votes
(a*b)*c= LCM(a,b)*c and a*(b*c) = a*LCM(b,c)= LCM (a,b,c)
Therefore (a*b)*c = a*(b*c) for all a,b,c belongs to N
answered
Oct 24, 2013
by
vijayalakshmi_ramakrishnans
Please
log in
or
register
to add a comment.
Related questions
0
votes
2
answers
Let \(\ast\) be the binary operation on \(N\) given by \(a\ast b=L.C.M\,.of\,a\,and\,b\). Find $\begin{array}{1 1}(i)\;\; 5 \ast7,\; 20 \ast 16 & (ii)\;\; Is\; \ast \;commutative?\\(iii)\;\; Is\; \ast \;associative? & (iv)\;\; Find\, the\,identity \, of \ast \, in N\\(v)\;\; Which \, elements\, of \, N\, are\, invertible\, for\, the\, operaation\,\ast ? & \;\end{array}$
asked
Nov 21, 2012
by
vaishali.a
cbse
class12
bookproblem
ch1
sec4
q6
p25
sec-b
math
0
votes
1
answer
Let\(A=N \times N \,and\, \ast \) be the binary operation on \(A\) defined by \( (a, b) \ast (c, d) = (a + c, b + d)\). Show that \(\ast\) is commutative and associative. Find the identity element for \(\ast\) on \( A \), if any.
asked
Nov 21, 2012
by
vaishali.a
cbse
class12
bookproblem
ch1
sec4
q11
p25
sec-b
math
0
votes
1
answer
Let \(\ast\) be the binary operation on \(N\) defined by \(a \ast b=H.C.F.\,of\,a\,\;and\;\,b\). Is \(\ast\) commutative? Is \(\ast\) associative? Does there exist identity for this binary operation on \(N\)?
asked
Nov 21, 2012
by
vaishali.a
cbse
class12
bookproblem
ch1
sec4
q8
p25
easy
sec-a
math
0
votes
1
answer
Let $\ast$ be the binary operation on $N$ given by $a \ast b =$ LCM of $a$ and $b$. $(iii)$ Is $ \ast$ associative?
asked
Mar 19, 2013
by
balaji.thirumalai
cbse
bookproblem
ch1
sec4
easy
p24
q6
q6-3
sec-a
0
votes
1
answer
Let \(\ast\) be a binary operation on the set \(Q\) of rational numbers as follows: $(v)\;\; a \ast b = \frac{ab}{4}$ Find which of the binary operations are commutative and which are associative.
asked
Mar 13, 2013
by
sreemathi.v
cbse
class12
bookproblem
ch1
sec4
q9
q9-5
p25
easy
sec-b
math
0
votes
1
answer
Let \(\ast\) be a binary operation on the set \(Q\) of rational numbers as follows: $(ii)\;\; a \ast b = a^2+b^2 $ Find which of the binary operations are commutative and which are associative.
asked
Mar 13, 2013
by
sreemathi.v
cbse
class12
bookproblem
ch1
sec4
q9
q9-2
p25
easy
sec-b
math
0
votes
0
answers
Let * be the binary operation on N given by p * q = LCM of p and q. Find (i) 12 * 56 (ii) whether * is commutative? (iii) whether * is associative (iv) identity of * in N.
asked
Jan 15, 2013
by
thanvigandhi_1
cbse
class12
modelpaper
2012
sec-b
q11
math
Ask Question
SUBMIT QUESTION
►
Please Wait
Take Test
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
5 Test Series
JEEMAIN
350+ TESTS
NEET
320+ TESTS
CBSE XI MATH
50+ TESTS
CBSE XII MATH
80+ TESTS
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...