Homework Help: Sketching a signal

1. Nov 28, 2009

zee3b

Sketch the following signal

u(t-3)-2u(t-8)+u(t-5)

if it was u(t-3)+u(t-5) I'd be able to sketch it, but the 2u(t-8) is confusing me
help me :(

I can draw the first part u(t-3) how do I add the second to the graph and then the third

2. Nov 29, 2009

LCKurtz

Take the 3, 5, and 8 terms in order. Start by drawing u(t-3). Then add u(t-5). You said you already can do that. Now just subtract 2u(t-8). You just add graphs by adding their ordinates.

3. Nov 29, 2009

zee3b

Thanks a lot, but Im confused on the 2u part. I can draw u(t-3) and u(t-5) but what is 2u? i'm used to u's

4. Nov 29, 2009

LCKurtz

You multiply u(t) by 2, so its values are 0 and 2.

5. Nov 30, 2009

zee3b

hey so this is my rough sketch of the first and last part how exactly will i fit in the -2u(t-8) in this. I did it in paint lol :( I'm a total noob but in the process of learning more help will be appreciated

6. Nov 30, 2009

zee3b

hey I was trying to work on it more, is it by any chance something like this

7. Nov 30, 2009

LCKurtz

Ta Daa! He gets it!

8. Dec 1, 2009

zee3b

Thanks <3

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