DM-Groups and Lattice-Q7

+1 vote

For a positive number c, consider the open interval G = (-c, c) of real numbers. For x, y \in G, define 

                                            x*y:=\frac{x+y}{1+xy/c^2}

Which one of the following statements is true?

(A).G is monoid but not group

(B).G is a group but not abelian

(C).G is semigroup but not a monoid 

(D).G is an abelian group

asked Jul 8 in Discrete Maths by gbeditor (10,700 points)
reshown Jul 9 by gbeditor

1 Answer

0 votes
D is correct one
answered Jul 9 by tsnikhilsharmagate2018 (18,160 points)
what will be the identity element?
Zero
because smallest positive number is always greater than zero.
can you show how u did ? that would be very helpful
Answer:
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