Boolean Algebra

[tintincute]

hi

i would like to know what is the value of this
!A + !A =
!A * !A =

is it both A?

i'm solving this one, and not really sure if i'm doing the right thing here.

first i changed the signs of the 3 equations which is this one:
¯¯¯¯¯¯¯¯¯¯¯
A * !B * C

into : !A + B + !C

can i just interchange the letters here and collect which can be canceled out?



¯¯¯¯¯¯¯ ¯ ¯ ¯¯¯¯¯¯¯¯¯¯¯
Y = A * B + A + C + A * !B * C


= !A * !B + !A + !C + !A + B + !C

= !A * !A + !A + !C + !C + 1


thanks & regards

 

[MrAl]

Hi there,


Check out:
DeMorgan's Theorem


and keep in mind that if you invert all inputs and outputs
that you also have to invert *all* logical connectives,
not just some.


Your examples:

!A + !A = !(!!A*!!A) = !(A*A) = !(A) = !A

and

!A * !A = !(!!A+!!A) = !(A+A) = !(A) = !A