# Shifting Operation !!

Discussion in 'Homework Help' started by Anthony Quah, Mar 13, 2008.

1. ### Anthony Quah Thread Starter Active Member

Dec 1, 2007
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I am doing Electronic Signal System, I got confuse how to obtain the formula of Shifting Operation ..from reference book "Continuous and Discrete Signals and Systems" by Samir S. Soliman pg. 10

i dont know how x(t) come out with t + 1 and -t + 3 ... i know the result of the shifting..but i dont know what make t + 1 and -t + 3 in the formula... would desperate need some help ... :-(

the attachment will give more detail about it...hoping to get some help..

Humble student,
Anthony

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2. ### Colin Mac Member

Mar 11, 2008
18
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When t is -1, x(t) is -1+1 = 0
when t is 0, x(t) is 0+1 = 1

When t is 2, x(t) is -2+3= 1
and when t is 3, x(t) is -3+3 = 0

3. ### Anthony Quah Thread Starter Active Member

Dec 1, 2007
80
0
i know that...but how we come out with the formula t+1 and -t+3 which extract from the graph ( in the attachment) ?

4. ### Colin Mac Member

Mar 11, 2008
18
0
You're not been clear. Are you asking where t+1 and -t+3 come from? There is no formula in that attachment.

5. ### Anthony Quah Thread Starter Active Member

Dec 1, 2007
80
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pls refer my first post...it consist of the graph..and by my ideal..it should able to generate formual t + 1 and -t + 3...i just want to know how to digest the graph in order to get those 2 formual.. ^^

6. ### Colin Mac Member

Mar 11, 2008
18
0
x(t) = t + 1, at t = -1 to 0
I've explained how in post 2

7. ### Anthony Quah Thread Starter Active Member

Dec 1, 2007
80
0
thank colin..kinda need time to digest it ^^

8. ### Colin Mac Member

Mar 11, 2008
18
0
Ok. It's not difficult. Look at it this way.
Looking at the graph, you can already see that x(t) = 0 when t is -1.

Another way to say that; x(t) = t + 1 when t is -1.
Why? Substitute -1 in for t:

x(t) = t + 1
x(t) = -1 + 1
x(t) = 0

**
Now find what x(t) is when t = 0 by putting 0 in for t, then look at the graph.

9. ### Anthony Quah Thread Starter Active Member

Dec 1, 2007
80
0
lol...i wish i was a mathematic genius...i look into it...thanks again for detail explaination...