22. consider a sequence (a,). a, = (-1" (-)let ak vn en then wnich of the following is true? l, limp-on b0 2. limsupn-o b1/2 3. liminf,-n b-1/2 4. 0s liminfp-e

22. Consider a sequence (a,). a, = (-1" (-)Let ak Vn EN Then wnich of the following is true? l, limp-on b0 2. limsupn-o b1/2 3. liminf,-n b-1/2 4. 0s liminfp-e ba S imsupn-co b S1/2 -