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Let * be a binary operation on Real numbers
defined by
a*b=ab/4
Given a*b=9
Find a and b
 one year ago
 one year ago
Let * be a binary operation on Real numbers defined by a*b=ab/4 Given a*b=9 Find a and b
 one year ago
 one year ago

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aman07Best ResponseYou've already chosen the best response.1
help ! @TuringTest , @Mani_Jha , @dumbcow ,
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
ok so we are given with the following information : a * b = ab/4 a*b = 9 this means \(\large{\frac{ab}{4} = 9}\) , right ?
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
Now , can you find what will be the value of "ab" ?
 one year ago

aman07Best ResponseYou've already chosen the best response.1
but how i find value of a and b ?
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
OK let me think for what to do after this, wait!
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
What we have yet as a first way to get rid of this is "hit and trial" but really I don't think that hit and trial will be a satisfactory method ....
 one year ago

aman07Best ResponseYou've already chosen the best response.1
well i knw to do that ..but there is some method using identity element and stuff
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
http://www.math.csusb.edu/notes/binop/node2.html I saw something here
 one year ago

aman07Best ResponseYou've already chosen the best response.1
:( i have that already in text.. i am stuck in this particular qn :(
 one year ago

HoaBest ResponseYou've already chosen the best response.0
i got it now. you have ab =36 that means a=3 and b =6. in binary system, 3= 10 (one zero) and 6 = 1001. make multiplication between them , you got exactly 36 in both code (binary and 10 system)
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
I tried to search some relative problems on binary operations on internet and I found this question : if : \(\large{a\alpha b = ab }\) then what will be \(\large{6\alpha 8 }\) . Of course that will be 2 but the question given is not exactly what we have in m
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
In my question (contd. from the previous post.) Ok, I have never learnt it but I thought it is a type of mental ability question... Is it also related to binary numbers ?
 one year ago

aman07Best ResponseYou've already chosen the best response.1
nope ..i think no one understands the type of qn i am referring to ..leave it ..i am leaving thanks for trying to help
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
@hoa "binary" doesn't mean "binary numbers"; it is just an operation you are doing with two numbers. Remember that "binary" stands for the numeral two.
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
Don't get depressed from the help here given by me @aman07 ... we have at present many users seeing this question and I am sure that some people are still here who are aware of these type of problems. Just have patience aman... wait for them to respond
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
We don't have sufficient information in this question.
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
Do you have the answer?
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
there are infinite ordered pairs of \((a,b)\).
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
Yes right @ParthKohli . There is no sufficient information to solve for a and b.. though i can say : a = 36/b and b = 36/a :)
 one year ago

mathsloverBest ResponseYou've already chosen the best response.2
but that values is where I am stuck ...
 one year ago

HoaBest ResponseYou've already chosen the best response.0
lol, interesting question and interesting asker
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
There are infinite values for \((a,b)\). We could have considered a particular pair if we had a much more restricted set/interval or the value of either of them.
 one year ago

ParthKohliBest ResponseYou've already chosen the best response.2
If you want to find \(ab\), then it's 36 :)
 one year ago

waltersBest ResponseYou've already chosen the best response.0
let \[x\]element R be the identity with respect to * ,then x*a=a*x=a for all a element R nowdw:1361630564587:dw dw:1361630761828:dw
 one year ago

mathteacher1729Best ResponseYou've already chosen the best response.0
ab/4 = 9 means... Step 1: multiply a times b Step 2: divide by 4 the result is 9. That means 9*4 = a*b = 36 So a and b could be 9 and 4 or 18 and 2 or 3 and 12 or any two digits that multiply to 36. We'd need more information to narrow down the possibilities of what a and b could be. Are they both positive? Are they both positive integers? Are they both positive integers within a certain range? etc.
 one year ago

aman07Best ResponseYou've already chosen the best response.1
well i am speAKing about the working given above by @walters using identity element but still i am having confusion
 one year ago

waltersBest ResponseYou've already chosen the best response.0
b*a does not neccesary means b multiply by a ,that's why i let x to identity knowing that i will have xa/4 and assign it to a but since a*b =9 this will also means that if a take x*a i will get the same value as a*b because of the binary operator
 one year ago

aman07Best ResponseYou've already chosen the best response.1
can u explain it step by step pleas e?
 one year ago

aman07Best ResponseYou've already chosen the best response.1
why doesnt b*a imply ba ?
 one year ago

aman07Best ResponseYou've already chosen the best response.1
i dont get the step ab=36 then how u write xa=36 ?
 one year ago

waltersBest ResponseYou've already chosen the best response.0
because * (it is the star operator not multiplications) they are not equal
 one year ago

waltersBest ResponseYou've already chosen the best response.0
do u know the defination of the binary operator
 one year ago

waltersBest ResponseYou've already chosen the best response.0
are doing Groups (abstract algebra)
 one year ago

waltersBest ResponseYou've already chosen the best response.0
ur questions means a*b if u take any 2 real numbers and map them the result will be in the form of multiplication of ur 2 real numbers divide by 4 and we know that tha mapping of those two numbers is equal to 9 tht's y i 've used 36 on my calculation because of the conditions i have
 one year ago
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