Defining a Step Function: Checking for Accuracy

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Homework Help Overview

The discussion revolves around defining a step function based on a provided graph. Participants are exploring the correct mathematical representation of the function, particularly in the context of engineering applications involving unit step functions.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants are attempting to define the step function using different forms, questioning the accuracy of each other's definitions. There is a focus on expressing the function in terms of unit step functions, with some participants expressing concerns about discontinuities and the behavior of the function at specific points.

Discussion Status

The discussion is active, with participants providing alternative definitions and questioning the validity of proposed forms. Some guidance has been offered regarding the need to express the function in a specific format, and there is an ongoing exploration of the implications of different definitions.

Contextual Notes

Participants note that the problem is situated within an engineering class context, which imposes specific requirements for expressing functions. There is mention of the need to consider values for t >= 0 and the absence of explicit discontinuity at t = 0 in the problem statement.

EvLer
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I just want to check if I got this right.
Given this graph, I need to define a step function:
Code:
         |
---------| C
         |
_________|_______________
         |
      -C |_________
         |

So, my definition is: C[-u(t) + u(-t)].
Thanks for checking this.
 
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f(x) = {c, x < 0}{-c, x > 0}, f(x) is undef at x = 0, though, |f(0)| = c
 
Thanks for reply.

I understand the form of the function, but this is for an engineering class, so we have to express everything in terms of u(t), etc. So, this is what I need for some-one to double check.
And they actually never say that there is a discontinuity at 0, because we have to find values for t >=0 and so on.
 
I don't think your definition will work so well. Let's say 0<c, and 0<t<c. What is the value of your function? well [tex]u_c(t)=0 \mbox{ for } t<c \mbox{ and } u_c(-t)=0 \mbox{ for } t<c[/tex] since t will just be negative it will still be less than c. So your function will not work in that case. I just worked from left to right to construct the definition and came up with
[tex]C[1-2u_c(t)][/tex]

Which seems to work for all t in R.

Regards
 

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