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= Hints for difficult problems =
 
= Hints for difficult problems =
Irrational numbers
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Irrational numbers<br>
Exercise 1.3.1
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Exercise 1.3.1<br>
 +
 
 
1.Write four  possible irrational numbers between 4 and 5.
 
1.Write four  possible irrational numbers between 4 and 5.
 +
 
Solution:  
 
Solution:  
 +
 
Consider the squares of 4 and 5
 
Consider the squares of 4 and 5
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42 = 16 and 52 = 25
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Square of 4 = 16 and Square of 5 = 25
We can also wright 4 and 5 as  
+
 
=4   and =5
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We can also write 4 and 5 as
 +
 +
√ 16 =4 and √ 25 =5
    
Between  and there exists
 
Between  and there exists
,,,,,,,
     −
2.Write four rational numbers between  and
+
√ 17 ,√ 18 , √ 19 , √ 20 , √ 21 , √ 22 , √ 23 , √ 24
Solution:
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root 2 ~1.414 and
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root 3 ~ 1.732
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Rational numbers of root2 and root 3 is in between 1.4 to 1.7 like 1.45,1.5,1.55, 1.6 ........
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  −
3.Prove that + is an irrational number
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Solution:
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Let us assume on contrary that is a rational number.
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Then there exists co-prime positive integers p and q such that
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        =
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    -=
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(-)2  =  ()2
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+2- 2.= 5
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              =
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p and q are integers
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is rational
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  −
But this contradicts the fact that  is irrational. 
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So, our assumption is wrong.
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Hence, is irrational
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Write an irrational 
      
= Project Ideas =
 
= Project Ideas =
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