Define the sequence {an} as follows:
a1 = 1 and for n ≥ 1, an + 1 = \((-1)^n\left(\frac{1}{2}\right)\left(\left|a_n\right|+\frac{2}{\left|a_n\right|}\right)\).
Which of the following is true?
1
lim sup an = √2
2
lim inf an =-∞
3
lim an = √2
4
sup an = √2