Is $x(t)=t \cdot u(t)$ a power signal or an energy signal? Please "show" me why - preferably using equations.

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    $\begingroup$ This question would do so much better with you showing your attempt. Your question is very basic, and it's really hard to see what you're missing to answer this. $\endgroup$ – Marcus Müller Feb 1 '18 at 7:18
  • $\begingroup$ Sounds like a “Please do my homework for me” request especially if the homework required the student to show the work and will not accept succinct answers such as “Power”, “Energy” or “Neither” or “Both” $\endgroup$ – Dilip Sarwate Feb 1 '18 at 15:29

To calculate the energy of a continuous signal you use the equation:
$$E_\infty = \int\limits_{-\infty}^{\infty} |x(t)|^2 dt$$
and for the power:
$$P_\infty = \lim\limits_{T\to\infty} \frac{1}{2T}\int\limits_{-T}^{T} |x(t)|^2 dt$$
If your signal has finite power ($0<P<\infty$) then it's a power signal. If the signal has finite energy then it's an energy signal (Notice that a signal can be neither type but can't be an energy and a power signal at the same time).

  • $\begingroup$ I am able to calculate the energy and show that it's infinity. I am having trouble calculating the power. I know that this signal is neither a power signal nor an energy signal but I get a finite value for power. (1/24)*T^2. $\endgroup$ – LaSzLo Feb 2 '18 at 2:44
  • $\begingroup$ I think you made a mistake while calculating the integral. And where did your limits disappear (when T goes to infinity so does your final result). $\endgroup$ – Crypted_39 Feb 2 '18 at 13:15

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