3 Draw a Truth Table using the following C Prove the follow
#3
Solution
a) (A+B)(A+B\')=A
(A+B)(A+B\')
=> AA + AB\' + AB + BB\'
=> A+AB\'+AB + BB’ {by Idempotent law: AA=A }
=> A+AB\'+AB + BB’ {by Complementary law: BB\' =0}
=> A(1+B\'+B) {by Absorption law}
=> A.1 {by Identity law}
=>A
b) XY + XY’= X
XY + XY’
=> X( Y + Y’ ) {by Distributive law}
=> X {by Complementary law: Y+Y’ =1}
c) X + XY = X
X + XY
=> X(1+Y) {by Distributive law}
=> X.1 { by Identity law: A.1=A }
=>X
d) X(X\' + Y) = XY
X(X\' + Y)
=> XX\' + XY {by Distributive law}
=> 0 + XY {by Complementary law: BB\' =0}
=> XY { by Identity law: A + 0 =A }
