# Math Help - De Morgan's second law Proof

1. ## De Morgan's second law Proof

Prove De Morgan's second law, ~(AB) = ~A v ~B, by applying De Morgan's first law to ~A and ~B.

I think I know how to do it but I just need some clarification to justify my answer... Thanks

2. Okay, then post your solution to see if it's correct.

P.S.: that should be $\sim(A\wedge B).$

3. I don't understand how this can be used to prove anything since $\sim(A\wedge B) \not{\equiv} \sim A ~\wedge \sim B$.

4. similar problem done here