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Abstract Algebra




                    Notes          5.  Why is ((X), , ) not a ring?
                                   6.  Show that { 0 } is a ring with respect to the usual addition and multiplication. (This is called
                                       the trivial ring.)

                                   7.  Prove that the only ring R in which the two operations are equal (i.e., a + b = ab    a,
                                       b  R) is the trivial ring.


                                                                    x x  
                                                                           
                                   8.  Show that the set of matrices      x R   is a commutative ring with unity.
                                                                        
                                                                     x x    
                                   9.  Let R be a Boolean ring (i.e., a  = a    a  R). Show that a = –a    a  R. Hence show that R
                                                               2
                                       must be commutative.
                                   Answers: Self  Assessment

                                   1. (b) 2. (a) 3. (c)  4. (a) 5. (a)

                                   14.7 Further Readings





                                   Books       Dan Saracino: Abstract Algebra; A First Course.
                                               Mitchell and Mitchell: An Introduction to Abstract Algebra.

                                               John B. Fraleigh: An Introduction to Abstract Algebra (Relevant Portion).




                                   Online links  www.jmilne.org/math/CourseNotes/
                                               www.math.niu.edu
                                               www.maths.tcd.ie/

                                               archives.math.utk.edu
































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