Need help with some math homework!

[WarDemon666]

I have to write a boolean table for (A+B)(AB)

I know you have to simplify it, but dont know how.

Im guessing its AB(A) + AB(B)?

Help please!!

Thanks!

 

[ActuaryTm]

Answer.

 

[TuxDave]

If A is 1 and B is 1....?
If A is 1 and B is 0....?
If A is 0 and B is 1....?
If A is 0 and B is 0....?

Look at the results and tell me if it looks awfully like a simplier function.

 

[WarDemon666]

i have to make a table, like a truth table, so i need a bunch of columns on top and I have to make a table,, I dont have the answers 🙁

 

[Pepsi90919]

if you paid attention in class.. 😕

 

[Pepsi90919]

Originally posted by: WarDemon666
i have to make a table, like a truth table, so i need a bunch of columns on top and I have to make a table,, I dont have the answers 🙁

for AND to be high, all conditions must be true
for OR to be high, at least one condition must be true

there's a start

 

[TuxDave]

Originally posted by: WarDemon666
i have to make a table, like a truth table, so i need a bunch of columns on top and I have to make a table,, I dont have the answers 🙁

Please tell me you're not considering an EECS major. Do you even know how to evaluate boolean expressions? Like... what does A+B equal if A is 1 and B is 1? or AB+A if A is 0 and B is 1?

 

[NutBucket]

Originally posted by: Pepsi90919
if you paid attention in class.. 😕

Seriously.

 

[WarDemon666]

as an example:

a(b+c) = ab+ac
table is:
a | b | c | ab | ac | b+c | a(b+c) | ab+ac
and underneath I know how to do it

 

[WarDemon666]

I do pay attention. but my teacher IS SUCK

 

[TuxDave]

Originally posted by: WarDemon666
as an example:

a(b+c) = ab+ac
table is:
a | b | c | ab | ac | b+c | a(b+c) | ab+ac
and underneath I know how to do it

000
001
010
011
100
101
110
111

Put that under A|B|C... figure out the rest.

 

[WarDemon666]

Originally posted by: TuxDave

Originally posted by: WarDemon666
i have to make a table, like a truth table, so i need a bunch of columns on top and I have to make a table,, I dont have the answers 🙁

Please tell me you're not considering an EECS major. Do you even know how to evaluate boolean expressions? Like... what does A+B equal if A is 1 and B is 1? or AB+A if A is 0 and B is 1?

A+B equal if A is 1 and B is 1?

= 1

AB+A if A is 0 and B is 1?

= 0

 

[dighn]

simply a table? there's no need to simplification. you only got 4 combos of a & b values

 

[ActuaryTm]

Originally posted by: WarDemon666
I do pay attention. but my teacher IS SUCK

Back in the dark ages (when I attended class), there were widely used tools known as text books. Perhaps there is a present day modern version of said tool?

 

[WarDemon666]

Originally posted by: TuxDave

Originally posted by: WarDemon666
as an example:

a(b+c) = ab+ac
table is:
a | b | c | ab | ac | b+c | a(b+c) | ab+ac
and underneath I know how to do it

000
001
010
011
100
101
110
111

Put that under A|B|C... figure out the rest.

I can do that. thats an example though. I dont know what to put for the columns for (A+B)(AB)

 

[dighn]

Originally posted by: WarDemon666


I can do that. thats an example though. I dont know what to put for the columns for (A+B)(AB)

err all possible combinations of a and b are 00 01 10 11

just evaluate the expression eg for ab = 00 you have (0+0)*0*0 --> don't tell me you don't know how to do this

 

[TuxDave]

Originally posted by: WarDemon666

Originally posted by: TuxDave

Originally posted by: WarDemon666
i have to make a table, like a truth table, so i need a bunch of columns on top and I have to make a table,, I dont have the answers 🙁

Please tell me you're not considering an EECS major. Do you even know how to evaluate boolean expressions? Like... what does A+B equal if A is 1 and B is 1? or AB+A if A is 0 and B is 1?

A+B equal if A is 1 and B is 1?

= 1

AB+A if A is 0 and B is 1?

= 0

Ok... so you do have the basic ideas.

So I gave you the start for A|B|C because that sequence will contain every possible combination of A, B and C. Under ab,ac and b+c, fill it in for each combination of a,b,c.

To evaluate a(b+c), you just look at the columns a and b+c and write 1 when they're both 1s.
To evaluate ab+ac, you just look at the columns ac and ab and write 1 when they're at least one is 1.

 

[TuxDave]

Originally posted by: WarDemon666

Originally posted by: TuxDave

Originally posted by: WarDemon666
as an example:

a(b+c) = ab+ac
table is:
a | b | c | ab | ac | b+c | a(b+c) | ab+ac
and underneath I know how to do it

000
001
010
011
100
101
110
111

Put that under A|B|C... figure out the rest.

I can do that. thats an example though. I dont know what to put for the columns for (A+B)(AB)

A|B|A+B|AB|(A+B)(AB)

Get the pattern? You just gotta break it down.

AB+B(AB+B) would have

A|B|AB|AB+B|B(AB+B)|AB+B(AB+B)...

I hope you get my example.

 

[WarDemon666]

Originally posted by: TuxDave

Originally posted by: WarDemon666

Originally posted by: TuxDave

Originally posted by: WarDemon666
as an example:

a(b+c) = ab+ac
table is:
a | b | c | ab | ac | b+c | a(b+c) | ab+ac
and underneath I know how to do it

000
001
010
011
100
101
110
111

Put that under A|B|C... figure out the rest.

I can do that. thats an example though. I dont know what to put for the columns for (A+B)(AB)

A|B|A+B|AB|(A+B)(AB)

Get the pattern? You just gotta break it down.

AB+B(AB+B) would have

A|B|AB|AB+B|B(AB+B)|AB+B(AB+B)...

I hope you get my example.

omg I cant believe I missed that.

THanks Ill try it out see what happens

 

[WarDemon666]

ok so for that question I got
(A+B)(AB) (the last column)
1
0
0
0

makes sense?

 

[TuxDave]

Originally posted by: WarDemon666
ok so for that question I got
(A+B)(AB) (the last column)
1
0
0
0

makes sense?

Depends... what are the A and Bs corresponding to each result?

 

[WarDemon666]

for and and b i put

11
10
01
00

 

[TuxDave]

Originally posted by: WarDemon666
for and and b i put

11
10
01
00

Looks good.

 

[WarDemon666]

Thanks a lot man 🙂😀

 

[ArmenK]

A | B | A+B | AB | (A+B)(AB)
0 | 0 | 0 | 0 | 0
0 | 1 | 1 | 0 | 0
1 | 0 | 1 | 0 | 0
1 | 1 | 1 | 1 | 1