1.
If lim⁡n→∞(2n2+n−2n2−n)=1λ\displaystyle \lim_{n \to \infty} \left(\sqrt{2n^2 + n} - \sqrt{2n^2 - n}\right) = \frac{1}{\sqrt{\lambda}} (where λ\lambda is a real number), then λ\lambda is equal to