Posted by Sami on Thursday, January 21, 2010 at 8:23pm.
Since this is not my area of expertise, I searched Google under the key words "multiplicative identity or multiplicative inverse". Here is information from one source:
MEAP Preparation - Grade 7 Mathematics
1.34 Multiplicative Identity and Multiplicative Inverse
If a/b is a rational number then
a/b x 0 = 0 x a/b = 0.
Example: 7/3 x 0 = (7x0)/3 = 0/3 = 0
Multiplicative Identity:
If a/b is a rational number then
1 x a/b = a/b x 1 = a/b
Example: 3/5 x 1 = 1 x 3/5 = 3/5
Therefore, one is the identity element for multiplication in rational number.
Multiplicative Inverse:
For every rational a/b (a, b are not equal to zero), there will be a rational number b/a is such that
a/b x b/a = 1
If the product of two numbers is one, we say that each number is the multiplicative inverse of the other.
Example: 2/3 x 3/2 = (2x3)/(3x2) = 6/6 = 1
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps.