Without referring to Theorem 5.3.8, prove part (c) of Corollary 5.3.9. Ifis a finite collection of countable sets, then iscountable.

L26 - 9 Now You Try It (NYTI): 1. Find each interval on which f(x)i sicesngadderangfrechofhe following functions. Find all relative extrema. Find the intervals on which the function is concave up and down, and ﬁnd each inﬂection point. 9 (a) f(x)= x + x (b)...