The number of viewers of a television series introduced several years ago is approximated by the function N(t) = (60 + 2t)2/3 (1 ≤ t ≤ 26) where N(t) (measured in millions) denotes the number of weekly viewers of the series at the end of the tth week. Find the rate of increase of the weekly audience at the end of week 2 and at the end of week 12.