Hi,
I was doing some practise on the inverse DTFT and already derive the sequence. But then the question asks about the energy of the sequence. Let's say the sequence that I got is x(n) = [sin (pi/4 n)] / [(pi) (n)]. To find the energy, I already found something like 2 * sum from n=1 to...
Hi all,
I've been wondering if there is any casio calculator that's similar to Ti-89? This is because I've been using casio calculators all my life and I've tried using Ti but I'm not used to it at all. If there is such casio calculator, do you know what's the difference between both of them...
Hi,
I have a question regarding on how to determine the impulse response of an LTI system which has the following conditions:
1).its input is x(n) = u(n) and output is y(n) = (1/2)nu(n) ,and
2).x(-1) = -1/3; x(0) = 1; x(1) = 1/2, and x(n) = 0 for all other values of n
My approach:
I...
Hi,
I need help in determining if a system is causal or not. So what I knew is that for a system to be causal is that it has to depend on past and present inputs. However, I don't completely understand the meaning of that definition. So for example if I have a system y(n) = x(n3) how do we...
Hi, I'm sorry if I post this question at the wrong section. I have a question regarding the energy sequence.
Qn: find the energy of the sequence x(n) = (1/3)^n u(n-1) + (1/2)^(n-1) u(n-2)
My Approach:
1). Energy = (sum from negative infinity to infinity) of |x(n)|^2
2). I know that if a...
oh I think I've figured the answer out already. Thanks! :smile:
so that's when x(n) = (1/2)nu(n). but what if the question is more complicated, something like x(n) = (1/2)(n-1) u(n-2) + (1/3)n u(n-1)? how do we compute the energy of the sequence then?
Thank you!
oh ya.. I think I've seen that somewhere, but I can't remember. Thanks for the recall.
So back to the question of the energy of x(n) = 0.5n u(n)
It means that it will be the sum from negative infinity to infinity of (1/4)^n
is that right?
hmm.. actually I'm totally clueless on how to derive the energy of the sequence. I mean what does it actually mean when they want the energy? :confused:
is there some kind of formula to it? this is because we just start a new quarter here, and the professor went on really fast. I tried to...
Hi, I'm sorry if I post this thread at the wrong section. I have a question regarding sequences.
Qn: if there is a sequence x(n) = (0.5)^n u(n), find the energies of the latter sequence of x(2n) and x(0.5n). Also, how the even and odd sequence of x(2n) and x(0.5n) relate to those of x(n)...
Hi,
I know how to do the Laurent expansions for a function that has two or more factors in the denominator (for eg: 1/(z-1)(z-2) ). But what if that there is only 1 factor in the denominator, like (z-1)/(z+1)?
I know how to do the computations for both of the cases, however, the thing that...
i know that for even function f(z) = f(-z) which means that the sum from n=0 to infinity of a_n z^n is equals to the sum from n=0 to infinity of a_n (-z)^n.
(note: a_n is the coefficient of the series)
Then this will give me an equation of a_n = a_n (-1)^n ---> conclusion: a_n can't be equal to...
Hi,
if let's say that there's an even function f(z) then how do we know if its Laurent decomposition (i.e. f(z) = f0(z) + f1(z) ) will be even functions and have even powers of z?
Any help will be greatly appreciated.
Hi,
I have 2 questions regarding how to expand power series.
1). Find the power series expansion of Log z about the point z= i - 2
2). Expand the function 1/(z^2 + 1) in power series about infinity
Any help will be greatly appreciated. This is because I am totally unsure about what...