(log2 x)^2 - 1 ≠ 0
(log2 x)^2 ≠ 1; log2 x ≠ +- 1;
sostituiamo:
log2 x = y;
1 / (y^2 - 1) + 1 / (y + 1) = 1 / (1 - y);
mcm = y^2 - 1 = (y + 1) (y - 1);
1 / [(y + 1) (y - 1)] + 1 / (y + 1) = - 1 / (y - 1);
1 + (y - 1) = - (y + 1);
1 + y - 1 = - y - 1;
2y = - 1;
y = - 1/2;
log2 x = - 1/2;
x = 2 ^ (- 1/2) ;
x = (1/2)^(1/2) = radicequadrata(1/2);
x = 1 / (√ 2) = √ 2 / [√ 2 * √ 2];
x = (√ 2) / 2.
Ciao @alby