Results 1 to 4 of 4

Math Help - Please help me understand this function

  1. #1
    Junior Member
    Joined
    Feb 2008
    Posts
    71

    Please help me understand this function

    Hi all. I can't remember what this type of function is called for the life of me, so sorry for being vague in the description. This is just part of a much bigger question and for some reason I get stuck at this part...

    I have two functions:


    f(t) = 1 for 0 < t < 1 and -1 for 1<t<2
    f(t-T) = 1 for 0 < t-T < 1 and -1 for 1<t-T<2

    so far so good.
    I'm supposed to know that f(t) = f(t-T) = 1 for 0<t<1-T, but how do I know this? I've not done a problem like this in like 3 years, so please give me some pointers.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28

    Re: Please help me understand this function

    This fucntion is called a hybrid,

    If f(t)=f(t-T) then maybe t=t-T and T=0?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Feb 2008
    Posts
    71

    Re: Please help me understand this function

    Quote Originally Posted by pickslides View Post
    This fucntion is called a hybrid,

    If f(t)=f(t-T) then maybe t=t-T and T=0?
    Yeah, that's what I first thought. The problem is that I start with f(t) then add the last term -T to get f(t-T). I really need it to become f(t)=f(t-T) = 1 for 0 < t < (1-T) to integrate this function properly.

    If I try it backwards: f(t) - f(t-T) = 0 so (0<t<1) - (0<t-T<1) = 0
    What is allowed to do here? I see I can't take each term like: (0-0<t-t+T<1-1).
    How do I make the range of f(t) "fit" into f(t-T) using math, basically.

    I'm thinking I can use some way to say that (0<t) and that t<(1-T) and just putting them together without breaking the mathematical logic.

    This is in a Signal & Circuit theory course at uni, all my math is done, but this type of problem is something that does not show up that often :P
    Follow Math Help Forum on Facebook and Google+

  4. #4
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2

    Re: Please help me understand this function

    The first function is a piece-wise defined function. The second is just the first function, but shifted. If you think about signs, you'll be able to see whether the second function shifts the first one to the right or to the left.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: November 18th 2010, 12:41 AM
  2. Replies: 4
    Last Post: September 18th 2010, 06:16 AM
  3. Function Theory [help needed to understand concepts]
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: August 16th 2009, 06:51 AM
  4. Finding domain of this function, don't understand it
    Posted in the Pre-Calculus Forum
    Replies: 6
    Last Post: November 7th 2008, 11:47 PM
  5. I dont understand the graph of this function
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: October 18th 2008, 08:31 AM

Search Tags


/mathhelpforum @mathhelpforum