Recent content by ColdStart

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    What is the derivative of a unit step function with discontinuities at -2 and 2?

    well then it turns out that its what i wrote in my first post, but in one book it shows -q(t+2)... that's why i got confused and was asking it here..
  2. C

    What is the derivative of a unit step function with discontinuities at -2 and 2?

    ok so: d/dt {(u(-2-t) + u(t-2)} = d/dt{ u(-(t+2)) + u(t-2)} = -q(t+2) + q(t-2) ?
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    Determination of a signal from its Fourier Coefficients

    no actually x[n] because its discrete time... wht if my period would be 40 or more? it would be more tedious then...
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    What is the derivative of a unit step function with discontinuities at -2 and 2?

    ok letsa say i have d/dt {(u(-2-t) + u(t-2)} I know that d/dt { u(t) } is q(t)... now is it correct to think that d/dt {(u(-2-t) + u(t-2)} = q(-2-t) + q(t-2) ?
  5. C

    Computation of Fourier Transform

    ok i'v been thinking more of this problem, now here is what i decided to do: lets say I am concentrating my attention on the 1st part of x(t) which is: t*exp(a)*exp(-a*t)*u(t-1), and i will compute X1(jw) for it first. i am changing t-1 to Tao, => Tao = t - 1, t=Tao+1, then i have the...
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    Integration limits for unit step

    thank you very much :)
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    Integration limits for unit step

    lol what u mean? i stil didnt get something? i'd be happy if u point out what else am i missing? :) stil have question... should i have Minus sign in front of 'a' in the integral then?
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    Integration limits for unit step

    ok because of this: i attached pic.
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    Integration limits for unit step

    just one more thing regarding this problem... now that we know my integration limits are froom -1 to 0... should i place '-' sign inside the integral before constant 'a'? because the unit step is negative? or not? i.e. should my integral be Int(-1,0 of: -a * dt) ?
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    Integration limits for unit step

    now i got it... thanks!
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    Computation of Fourier Transform

    Homework Statement x(t) = t*exp(a)*exp(-a*t)*u(t-1) - exp(a)*exp(-a*t)*u(t-1) I need to find X(jw)... Homework Equations how to apply properties of Fourier transform to get an answer? Because i know that the only effective method for this.. The Attempt at a Solution For...
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    Integration limits for unit step

    Ok, let me c if i got it correct, rewriting: u(-(t+1)) - u(-t), I am attaching picture.. the first part of this expression is shown with black, the second part which is u(-t) is shown in red.. now its clear that integral limits are from 0 to t+1? But.. however tho.. my original problem...
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    Integration limits for unit step

    hello, if i have an integral like: Int( [-u(-t) + u(-t-1)] * a * dt, -Inf, +Inf)... where a is some constant.. what would be the correct initegration limits? the most important here is to determine correctly the integration limits.. if i solve the inequalities: -t > 0 => t < 0 -t-1 > 0...
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