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Please help me for midterm ON GRADE 11 boolen algebra

  1. May 28, 2008 #1
    i really need someone to me verify my answer. i will be having my exam next week and iam stuck . please iam really stuck on some of this question.

    ' is not


    '' its not, not


    1. F = B.(A''. B' . C')

    2. F = A. (A''+ B' + C')

    3. F = A . (B''.C') + A . (B + C')

    4. F = (A'' + B'') + A . B

    5. F = A'.B'+C'+A.(B'+C')

    6. F= A'. B+ D.(C+D') + A. B' . C' . D

    7. F = A. C'.D'+(A''.B'.C') + (A''.B')

    8. F = A.B'.C' + A'.B.C.D + A'.B.C'+A.B'C.D


    MY ANSWERS

    1. F=BA'.BC'
    2 F=A.AB.AC'
    3. F= AB + AC
    4. F=A.B
     
    Last edited: May 28, 2008
  2. jcsd
  3. May 28, 2008 #2

    berkeman

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    Staff: Mentor

    Could you please explain your notation? What is the difference between ' and " ? Also, could you please explain what techniques you are using to derive your answers? We do not give out answers to homework/coursework questions here on the PF, but we can provide tutorial help so that you can figure out the answers yourself.
     
  4. May 28, 2008 #3
    ' is not

    '' its not, not


    I just need someone to check my answers and i would really apreciated
     
    Last edited: May 28, 2008
  5. May 28, 2008 #4

    berkeman

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    Staff: Mentor

    Um, okay. What would not not always equal?

    And we really do need to see what you are doing to derive your answers. What distributive rules are you using, for example? Please show your step-by-step work for each of the answers, so that we can see how you worked them out. Alternately, show the Karnaugh maps you used, if that's how you solved the problems.
     
  6. May 28, 2008 #5

    berkeman

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    Staff: Mentor

    As I said, we do not give out answers here. We also do not just check answers. That would be cheating. Please show all of your work.
     
  7. May 28, 2008 #6
    step by step solution

    1. AB'+BB'+BC'
    = AB'+BC'

    2. AA.AB.AC'
    =A.AB'.AC'

    3. AB+AC+AB+AC
    =AB+AC

    4. (A.B)+A.B
    =A.AB.AB.B
    =A.B

    i dont know if this is right, also iam working on the other answers
     
    Last edited: May 28, 2008
  8. May 28, 2008 #7

    berkeman

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    Staff: Mentor

    That's much better, but it would still help us if you could say what rule you are using in each step. Like the "Monotone Laws" listed at wikipedia.org (with v = OR and ∧ = AND):

    from http://en.wikipedia.org/wiki/Boolean_algebra_(introduction)

     
  9. May 28, 2008 #8
    yes iam using those laws but i dont know if my answers are right or wrong
     
  10. May 28, 2008 #9

    berkeman

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    Staff: Mentor

    Yes the laws are right. They were on wikipedia, after all :rolleyes:

    But seriously, what I mean is to annotate each line in your solution with a comment on what law you've used to make that step. Like

    1. F = B.(A''. B' . C')
    = AB'+BB'+BC' (which law or laws were used in this step?)
    = AB'+BC' (what property of BB' did you use?)
     
  11. May 28, 2008 #10
    step by step solution

    1. AB'+BB'+BC' (use complements laws B.B=0)
    = AB'+BC'

    2. AA.AB'.AC' ( Use idempotency A.A= A)
    =A.AB'.AC'

    3. AB+AC+AB+AC(use idempotency A+A=A)
    =AB+AC

    4. (A.B)+A.B ( i think this one is wrong)
    =A.AB.AB.B
    =A.B
     
  12. May 28, 2008 #11

    berkeman

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    Looks like you're getting the hang of it. On #4...

    First of all, I've never seen not-not, but whatever. Anything not-not would be itself, I would think. So:

    4. F = (A'' + B'') + A . B = (A + B) + A . B

    But you can use the Absorption #2 listed from wikipedia, or just truth tables to simplify that further...
     
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