Find the interior and boundary of each of the follwing sets: a. [0,1) b. Q c. R\Q d. R e. (-inf,-2) U {1/n: n is a natural} U [1, inf) I think a) (0,1) b) empty set c) empty set
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Originally Posted by Jdg6057 Find the interior and boundary of each of the follwing sets: a. [0,1) b. Q c. R\Q d. R e. (-inf,-2) U {1/n: n is a natural} U [1, inf) I think a) (0,1) b) empty set c) empty set Yes, that's right so far. d) $\displaystyle \mathbb{R}$ e) $\displaystyle (-\infty,-2)\cup(1,\infty)$ Note that $\displaystyle int(A)\cup bound(A)=cl(A)$, so what are the boundary points of each set?
Last edited by redsoxfan325; Oct 16th 2009 at 08:26 AM.
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