Discussion Forum



1)

If $x = 1 + \sqrt{2}$ and $y = 1-\sqrt{2}$, find the value of $(x^{2}+y^{2}).$


A) 3

B) 4

C) 5

D) 6

Answer:

Option D

Explanation:

$ (x^{2}+y^{2}) = (1 +\sqrt{2}) + (1 -(\sqrt{2}  ^{2}) $
$= 2 [1^{2} + \sqrt{2}  ^{2}] = 2\times 3 = 6.$