2. Let f be a continuous function defined on interval[a,b]. If f (a) f (b) − f (a) − f (b) +1＜0 , then there exists a number c between a and b such that f(c) =1 . (A)O(B)X

6. We already know that the series is convergent. Now, rewrite the series by combining 2n consecutively positive terms in the series, then followed by 2n consecutively negative terms, where n = 1, 2, 3, …, to get a new series as follows:+... , then the new series is still convergent. (A)O(B)X