Question

Se considera E(x)=($(x \sqrt{2} +1 )^2 - (x \sqrt{2 +1} ) ( x \sqrt{2} -1 ) - 2x \sqrt{2}$
Aratati ca E(x)=2

Answer 1

Cred ca acolo unde ai scris x√2+1 era de fapt x√2 +1
In fine,
(x√2 +1)² = 2x²+1+2x√2
(x√2 +1)(x√2 -1)= 2x²-1
2x²+1+2x√2-2x²+1= (se reduc 2x² si 2x√2) 1+1= 2