1. Oct 17, 2006

### angel23

why is Y(t)=X(2t) time varient ???????

2. Oct 17, 2006

### Raihan

AS you know Angel the rule here by the mentors are that we have to show that we tried doing it. So please show what is your approach and after that by the rule of this forum I can help you.

3. Oct 17, 2006

### angel23

i looked at my function and found no parameters containing the variable t so i said it is a time invarient system..
am i right or wrong????
is there any other way i can use to check whether my function is time varient or time invarient???

4. Oct 17, 2006

### es1

5. Oct 18, 2006

### Raihan

FOR TIME INVARIANT SYSTEM

[ tex ] x_1(t)------>y_1(t) [ \tex ]
[ tex ] x_2(t)= x_1(t-T) [\tex] ---keep this equation same
[tex] x_2(t)------>y_2(t) [\tex]
[tex] y_2(t)=y_1(t-T) [\tex]

If all these conditions are true for that function then YES its TIME INVARIANT else its TIME VARYING. So if you put Y(t)=X(2t) here and you will see that eqn (3) is not equal to eqn(4). So its TIME VARYING.