# 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

Thanks <3