output for decoder and demultiplexer

[vead]

I need some help to understand truth table

1 to 2 demultiplexer
input I
select line S
output D0, D1

I  S  Do  D1
0  0
0  1
1  0
1  1

how to determine D0 and D1 by boolean expression ?

2 to 4 decoder
A is the address and D is the dataline

A1  A0    D3  D2  D1  D0
0    0      
0    1      
1    0      
1    1

how to determine D0 to d4

 

[(*steve*)]

Perhaps you should start by describing in words what the devices do. What are you told about them?

 

[vead]

Perhaps you should start by describing in words what the devices do. What are you told about them?

ok look this table
I don't understand the output value of circuit
how to determine output of decoder and demultiplexer

decoder truth table

A1  A0      D3    D2    D1  D0
0    0       0    0     0     1
0    1       0    0     1     0
1    0       0    1     0     0
1    1       1    0     0     0

demultiplexer

I  S  Do  D1
0  0  0    0
0  1  0    0
1  0  1    0
1  1  0    1

 

[(*steve*)]

Perhaps you should start by describing in words what the devices do. What are you told about them?