# simple Signal modeling help

Discussion in 'Homework Help' started by zicker, Sep 23, 2010.

1. ### zicker Thread Starter New Member

Jul 15, 2009
8
0
I'm having a bit of trouble with this HW problem

http://i160.photobucket.com/albums/t197/aeberet/hw.jpg?t=1285299828

I can't figure out how to do g4(t) and I could use some help on g5(t).
I've been looking around google, but I can't find any good sight to help explain time-scaling. I know the answer is probably right in front of me, but I don't see it. I would appreciate some help.

2. ### Ghar Active Member

Mar 8, 2010
655
72
For g4 think of adding together two upside down triangles - they make a square.

3. ### Georacer Moderator

Nov 25, 2009
5,142
1,266
That sounds rather complicaded to implement. Just think it this way: Say you take g and g1 and overlay them so that they have a common base line.
At the beginning of the line g will be 1 and g1 will be zero. Sum is 1.
At the middle of the line g and g1 will be 0.5. Sum is 1.
At the end of the line g will be zero and g1 will be 1. Sum is 1.
Does that make anymore sense?

G5 is g time-scaled and time-shifted. Read about time-scaling and it will be a piece of cake.

4. ### zicker Thread Starter New Member

Jul 15, 2009
8
0
Thanks for the reply, it really did help.

For g4 I have g(t-1/2) + g1(t+1/2)

for g5 I have 15g(1/2t -1)

I appreciate the help and if I have any other problems I'll be sure to post them.