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windsylph
Discrete Math: Union from i = 1 to infinity of A_i where A_i = (0,i), that is, the set of real numbers x such that 0 < x < i? I answered {x in R | 0 < x < infinity} but I'm worried about the correctness of that answer, since wouldn't this apply if A_i = (0,i] also?
first answer was right, but you don't need to write the \(\infty\) on the right
\[\bigcup_{i=1}^\infty A_i \quad \text{where}\quad A_i=(0, i)\]I'm going to agree with @satellite73 here. I see nothing wrong with your answer. And it would be the same if \(A_i=(0, i]\). It's just a different way of writing things.