Question Number 205528 by hardmath last updated on 23/Mar/24
$$\mathrm{Let}\:\:\:\forall\mathrm{x}\:\in\:\mathrm{A}\:\rightarrow\:\mathrm{x}\:\in\:\mathbb{R} \\ $$$$\mathrm{And}\:\:\:\mathrm{card}\left(\mathrm{A}\right)\:>\:\mathrm{card}\:\mathrm{N} \\ $$$$\mathrm{Prove}\:\mathrm{that}: \\ $$$$\mathrm{card}\left(\mathrm{A}'\right)\:>\:\mathrm{card}\:\mathrm{N} \\ $$
Answered by Berbere last updated on 24/Mar/24
$${what}\:{is}\:{A}'\:\:? \\ $$
Commented by hardmath last updated on 24/Mar/24
$$ \\ $$Dear profesdor, card(A)- is a power of set A'- is a derivative of set A, the condition says that A is a non-countable set, it is necessary to prove that the derivative of A is also a non-countable set...
Commented by Berbere last updated on 25/Mar/24
$${i}\:{see}\:\:{in}\:{french}\:{we}\:{say}\:\:{points}\:{Limite} \\ $$$${i}\:{will}\:{give}\:{answer} \\ $$