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
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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