Question

prove that (x+ y)2 + (x - y )2 = 2 (x2 + y2)​

Answer 1

$\huge\underbrace\red{\dag {\mathfrak{Answer}} \dag}$

Yes here LHS = RHS

Answer 2

Answer:

identities:

(a+b)² = a² + 2ab + b²

(a-b)² = a² - 2ab + b²

(x+y)² + (x-y)²  

= x² + 2ab + y² + x² - 2ab + y² = 2        [using the above mentioned identities]

= x² + y² + x² + y²                                   [ + 2ab and - 2ab cancel each other ]

= 2x² + 2y²

= 2 (x² + y²)