Saturday, 28 September 2013

Chap 1 Rational Numbers

Chap 1
Rational Numbers
Some Important Facts :-
1.      The numbers which can be expressed in the form of p , when P/q and q both are natural numbers, are called fractions, like 2/5 , 7/3 etc. Here, p is  numerator and q is                              denominator of fraction.
2.    If the denominator of fraction is greater than its numerator then the fraction is known as proper fraction, but if numerator is greater than its denominator then the fraction is known as improper fraction.
  1. If the numbers p and q in a fraction P/ Q have no common factor other
than 1, then P / Q is in its simplest or lowest form. Suppose k is the other common factor of p and q, then we take p = mk and q = nk, hence P/ Q =   m x k = m/ n Here, p/n and m/n are said to be equivalent fractions.                                              nx k                       
    4.  (i) If the denominators of fractions are not equal, then we make their numerator will be greater. For example:
                In 3/ 5 and 1 / 5 , 3 /5 is greater. i.e. 3/ 5 > 1/5 \ 3 > 1
 (ii) If the denominators of fractions are not equal, then we make  their denominators equal and compare them.
 5. In fraction p /q , p and q are positive integers. If we take p and q be any integers and q are positive than zero i.e., q ≠ 0, then p/q  is  known as rational number.
6. Two rational numbers p/q  and r/s are said to be equivalent if p x s = q x r.

7. Every rational number can be represented on the number line.
8. If p/q and r/s are two rational numbers and q, s ≠ 0 then p/q > r/s if p x s > q x r
9. If p/q and r/s are two rational numbers and q, s ≠ 0 then p/q < r/s if p x s <  q x r      
10. The absolute value of a number is equal to or greater than the  
          number itself.