2,251 reputation
822
bio website
location
age
visits member for 4 years
seen yesterday

Dec
14
awarded  Yearling
Nov
21
comment Proof with Positive Symmetric Matrices
Just work it out by the definition of SPD $x^TKx > 0, \forall x \in \mathbb R^n$.
Nov
15
comment Matrix Differential Equation with a Skew-Symmetric Matrix
Please provide an example
Sep
11
comment Why does $x^{(1/\ln(x))} = e$?
Take the natural log of both sides and insight is not far off.
Jun
12
comment Curve fitting to connect certain points
What is the significance of the blue curve? Why are the interpolation points represented as triangles? How do they affect/constrain the black curve?
May
22
comment How to calculate per unit costs for multiple items
Does 'x' represent a variable or multiplication?
May
22
comment Time-varying frequency waveform
A couple of things to consider. First you should make sure that the requested frequency is no more than 1/2 of the signal sample frequency to avoid aliasing. Second, what you are trying to do here is frequency modulation. If you read the Wikipedia article, you will see that it generates higher frequencies than expected. Third, depending on how the wave is synthesized, you need to adjust the phase of the signal to make sure it is continuous. I am not sure if your method does that.
May
19
comment Laplace transform of unit step function
By definition: $f(t) = \begin{cases} t, & \text{$0 \le t \le 1 $} \\ 0, & \text{$1 \lt t \lt \infty$} \\ \end{cases}$
May
19
comment Laplace transform of unit step function
The function is zero for $t>1$. You don't need to integrate it.
May
19
answered Laplace transform of unit step function
May
19
comment Laplace transform of unit step function
Can you use a Laplace transform table? The function above is only useful if you are using a table. Otherwise just integrate from 0 to 1, i.e. $F(s)= \int_0^1e^{-st}tdt$.
May
19
comment Laplace transform of unit step function
The function you want to use is $f(t)=t(u(t)-u(t-1))$.
May
14
comment Gaining Linear Algebra Intuition — Subspaces
This set of lectures helped me a lot: ocw.mit.edu/courses/mathematics/….
May
14
revised Gaining Linear Algebra Intuition — Subspaces
Thought this tag may help clarify OP intent.
May
7
comment Show that exist a rotation $r$ such that $r(u)=v$
Hint: You need the axis-angle representation of a rotation (see: en.wikipedia.org/wiki/Axis_angle). You can use the dot product to find the angle and the cross product to find the axis.
Mar
11
reviewed Approve Double Angle Formula?
Mar
8
reviewed No Action Needed What are the odds of a specific 5 digit combination appearing within an 8 digit combination of numbers in any order/any recurrences from 0-9.
Mar
8
reviewed Approve Why does the following nonlinear system have 21 solutions?
Mar
8
reviewed Approve Is the function $f(x,y) = \sin(\frac{r}{\theta}), f(0,0) = 0$ continous at the point $ (0,0)$?
Feb
27
reviewed Approve Let $T$ be a tree of order $n$. Why is the complement $\neg T$ of $T$ the same size as $K_{n-1}$?