untitled

(Barré) #1

Formula 1. (ab)^2 a^2  2 abb^2


Formula 2.(ab)^2 a^2  2 abb^2


Remark : It is seen from formula 1 and formula 2 that, adding 2 ab or  2 abwith


a^2 b^2 , we get a perfect square, i.e. we get, (ab)^2 or (ab)^2. Substituting
binstead of b in formula 1, we get formula 2 :
{a(b)}^2 a^2  2 a(b)(b)^2
That is, (ab)^2 a^2  2 abb^2.


Corollary 1.a^2 b^2 (ab)^2  2 ab


Corollary 2. a^2 b^2 (ab)^2  2 ab
Corollary 3. (ab)^2 (ab)^2  4 ab


Proof : (ab)^2 a^2  2 abb^2
= a^2  2 abb^2  4 ab
= (ab)^2  4 ab
Corollary 4. (ab)^2 (ab)^2  4 ab
Proof : (ab)^2 a^2  2 abb^2
= a^2  2 abb^2  4 ab
= (ab)^2  4 ab


Corollary 5.
2


2 2 (a b)^2 (a b)^2
a b
  


Proof : From formula 1 and formula 2,


a^2  2 abb^2 (ab)^2
a^2  2 abb^2 (ab)^2

Adding, 2 a^2  2 b^2 (ab)^2 (ab)^2


or, 2 (a^2 b^2 ) (ab)^2 (ab)^2

Hence,
2

( ) ( )
( )

2 2
a^2 b^2 ab ab

Corollary 6.


2 2

2 2
̧ ̧
¹

·
̈ ̈
©

§ 
̧ ̧ 
¹

·
̈ ̈
©

§ 
a b a b
ab

Proof : From formula 1 and formula 2,


a^2  2 abb^2 (ab)^2
a^2  2 abb^2 (ab)^2

Subtracting, 4 ab (ab)^2 (ab)^2

Free download pdf