Question

Calcule :
[(a+b)² + (a-b)²]² =

Answer 1

[(a+b)² + (a-b)²]² =

[ a² + 2ab + b² + a² - 2ab + b²]²
[ a² + b² + a² + b²]²
[ 2a² + 2b²]²

4a^4 + 8a²b² + 4b^4
          ou

4(a^4 + 2a²b² + b^4)

Answer 2

$[(a+b) ^{2} +(a-b) ^{2} ] ^{2} = [ a^{2} +2ab+ b^{2} + a^{2} -2ab+ b^{2} ] ^{2} [2 a^{2} +2 b^{2}] ^{2} 4a^{4}+4 b^{4}$