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Homework Help: DeMorgans Law using NAND gates

  1. Apr 18, 2012 #1
    1. The problem statement, all variables and given/known data
    I am struggling with the diagram of this question. Can anyone help? I would have loaded my diagram but unsure how to do it. This is the question:

    Starting with the following statement (A+B).(A+C), show how this can be implemented using NAND gates using DeMorgans law.


    2. Relevant equations

    3. The attempt at a solution
    After doubly negating, I obtained (A.B) + (A.C). And this is where I get stuck.
    Please help. I have a deadline looming this week.
  2. jcsd
  3. Apr 19, 2012 #2


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    Homework Helper

    Try to expand and then simplify the expression first.

  4. Apr 19, 2012 #3
    Thanks for a response. I am okay with the maths but unsure about the actual diagram. Any pointers? Thanks.
  5. Apr 19, 2012 #4


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    Homework Helper

    The double-negated (A+B).(A+C) is not A.B+A.C.

    If you do not know how to draw the diagram, see http://www.kpsec.freeuk.com/gates.htm. Copy the figures and construct the circuit from them.
    If you do not know how to upload it into your post, click on "Go Advanced".

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