여집합의 확률 공식 증명.

= Theorem =
For any event $A$ ,
 $P(A^c)=1-P(A)$

= Proof =
$1 = P(S)$ (by axiom of probability)  // [[확률공리,probability_axiom]] later
 $=P(A\cup A^c)$ 
 $=P(A)+P(A^c)$

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Up: [[여러가지증명]] [[집합set]]