[hashom]

i have exam and am not sure about my answer if someone can correct to me if its wrong

and this is my answer

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[mojo666]

On the diagram that you filled in, you copied things incorrectly for Fs. For example, you clearly marked the NOR gate with the expression NOT(B or C) which is correct, but in your final Fs this portion is written NOT(B ) or NOT( C) which is incorrect. Go back and make sure your expression is written correctly.

Since you started out with the wrong expression, you will not derived the correct simplification. Even so, your application of identity laws is incorrect. For example, you applied DeMorgan to two expressions NOT(B and A) as well as NOT(B ) or NOT( C). All you did was alternate the "AND" and "OR" operators. However, for DeMorgan you need to 1) Negate the whole expression. 2) Alternate the operator. 3)Negate the parameters of the operator. So, if we Apply DeMorgan to NOT(B and A)

1)Negate the expression:  B and A
2) alternate the opperator: B or A
3)Negate the parameters: NOT(B ) or NOT(A)

I suggest you do some heavy reviewing of logical identities. Don't just try to remember things like the 3 steps I gave for DeMorgan. Try to understand what is actually being described. For example A and B is a true statement when A is true and B is true. So, the statement is not true when either A is not true or B is not true. You can see from that sentence that NOT(A and B )=(NOT(A) or NOT(B )) which is all that DeMorgan's law is saying.

This post has been edited by mojo666: 28 November 2013 - 08:24 PM