Tagged Questions
2
votes
2answers
37 views
I need to calculate the period, I need help to verify my answer
I need to determine if $x(t) = 9\cos(2t) + 4\sin(\pi t)$ is periodic. If it is periodic I need to find the period. this what I have done
\begin{align*}
T_0 &= 2\pi/w\\
T_1 &= 2\pi/2 = \pi \\
...
0
votes
0answers
131 views
Fourier Series Coefficients for Signals
The question is:
We specify the fourier series coefficients of a continuous-time signal that is periodic with period 4. Determine the signal x(t).
$a_k=\begin{cases}
0, & k=0\\
...
0
votes
1answer
66 views
Fourier Series with Signals
So the question is:
Determine the fourier series representations for the following signal:
Here the formula for the fourier series
$$C_k=\frac{1}{T}\int_T \! x(t)e^\frac{-j2\pi kt}{T} \, \mathrm{d} ...
7
votes
2answers
4k views
Integration of sawtooth, square and triangle wave functions
Context
After a discussion about how to plot the results of a frequency modulation between two signals on Stack Overflow, I understood that I need to find the time-integral of the following wave ...
2
votes
1answer
377 views
Derivative of a random variable w.r.t. a deterministic variable
I'm reading about time series and I thought of this procedure: can you differentiate a function containing a random variable.
For example:
$f(t) = a t + b + \epsilon$
where $\epsilon \sim N(0,1)$. ...
2
votes
2answers
226 views
Can it be proven that such functions don't exist?
We are given $x_1,x_2 \in \mathbb{R}$ and we want to find two functions $v_1(t),v_2(t)$ such that:
$$x_1x_2 = \int_{-\infty}^{\infty} v_1(t)-v_2(t) dt$$
A very interesting restriction that we have ...
0
votes
3answers
933 views
How to sketch a sinc function by hand?
I have to do this for an upcoming exam, but cannot find anywhere (in the textbook or online) how to do this.
I only really need to know a couple points to plot it... when x = 0, and then the earliest ...
1
vote
2answers
72 views
Preserving the extrema of one function after applying another
Suppose we have some function $f(x)$ with local extrema at $x_1, x_2, \dots$, and a second function $g(x)$ which is continuous, strictly increasing and non-zero everywhere over the range of the $x_i$. ...
