Reputation
3,315
Next privilege 5,000 Rep.
Approve tag wiki edits
Badges
9 29
Impact
~117k people reached

Feb
3
comment How do you show a set is dense? For example, is the set of all ration numbers $p/q$ with $q ≤ 10$ a dense set?
It is the minimal distance between two numbers of your set. What would you expect for a dense set?
Feb
3
comment How do you show a set is dense? For example, is the set of all ration numbers $p/q$ with $q ≤ 10$ a dense set?
If you restrict $q$ to be smaller than $10$, how close could you for example approximate $0.15$ in the best case?
Feb
2
comment Accelerating linear solve in MATLAB for a specific type of matrices
The system is indeed not sparse, just very small. MATLAB will be left behind later on, this is just for testing purpose, however a faster code would also allow better testing. Thanks for the reference, I will take a look at it!
Feb
1
asked Accelerating linear solve in MATLAB for a specific type of matrices
Jan
1
revised Largange polynomial second order derivative
added 14 characters in body
Dec
16
answered Largange polynomial second order derivative
Dec
8
awarded  Popular Question
Dec
6
comment Quadratic optimization: Why does the formula have “$\frac{1}{2}”$ in front?
Usually the $\frac12$ is due to the fact that it vanishes when differentiating w.r.t $x$.
Nov
16
comment existence directional derivatives
Do you know the definition of the directional derivative?
Nov
12
awarded  Yearling
Nov
12
comment Which functions are in $C_0^\infty$, except for the Bump function
Thanks for all the comments, I feel stupid for not realizing, that I could just combine $\phi$ with another function. If any of you would take the time to write your comment as an answer I will gladly accept it. Thanks!
Nov
11
asked Which functions are in $C_0^\infty$, except for the Bump function
Oct
14
revised Equation - what first?
deleted 34 characters in body
Sep
20
comment How can I find the convolution of these two functions?
@B.Lee , I didn't go through the calculation, but I would split the integral at $t$, i.e. $\int_{-\infty}^\infty = \int_{-\infty}^t + \int_t^\infty$.
Sep
20
comment How can I find the convolution of these two functions?
I would consider the cases $t<0$, $t=0$ and $t>0$. Then you can split the integral with $t$ dependency.
Aug
29
comment How do i evaluate $ \bigtriangleup^{10}(1-ax)(1-bx^{2})(1-cx^{3})(1-dx^{4}) $
I'm not exactly sure, what you are planning to do, but if the differentiation is of order 10, you might want to check the maximum order of your polynomial.
Aug
6
revised Approximation of a negative exponential model?
edited body
Aug
6
answered Approximation of a negative exponential model?
Aug
3
comment Consider the function f(x)=sin(x) in the interval x=[π/4,7π/4]. The number and location(s) of the local minima of this function are?
The reason, why $\pi/4$ might sound confusing, is because it is no global minimum, but a local minimum at the left boundary.
Aug
3
comment Consider the function f(x)=sin(x) in the interval x=[π/4,7π/4]. The number and location(s) of the local minima of this function are?
Thanks for adding the local minima at $\pi/4$. +1