If G and H are abelian prove that G times H is abelian Suppo
     If G and H are abelian, prove that G times H is abelian  Suppose the groups G and H both have the following property:  Every element of the group is its own inverse.  Prove that G times H also has this property.  Powers and Roots of Group Elements  Let G be a group, and a, b  G. For any positive integer n we define a\" by  If there is an element x  G such that a = x^2 we say that a has a square root in G Similarly, If a = y^3 for some y  G, we say a has a cube root in G. In general a has an n the root in G if a = z^n for some z  G. Prove the following:  (bab^-1)^n = ba^n b^-1 for every positive integer n. Prove by induction. (Remember that to prove a formula such as this one by induction, you first prove it for n = 1; next you prove that if it is true for n = k then it must be true for n = k +1. You may conclude that it is true for every positive integer n Induction is explained more fully in Appendix C.)  If ab = ba then (ab)^n = a^n b^n for every positive integer n Prove by induction. If xax = e, then (xa)^2n =a^n.  If a^3 = e, then a has a square root.  If a^2 = e, then a has a cube root.  If a^-1 has a cube root so does a.  If x^2 ax = a^-1, then a has a cube root  If xax = b, then ab has a square root.    
 
  
  Solution
Ans-
o perform an elementary column operation on A, an r x c matrix, take the following steps.
Let\'s work through an elementary column operation to illustrate the process. For example, suppose we want to interchange the first and second columns of A, a 3 x 2 matrix. To create the elementary column operator E, we interchange the first and second columns of the identity matrix I2.
Then, to interchange the first and second columns of A, we postmultiply A by E, as shown below.
Note that the process for performing an elementary column operation on an r x c matrix is very similar to the process for performing an elementary row operation. The main differences are:
Test Your Understanding
| 
 | 
 | |||||||||||||
| I2 | E | 

