# Tag Info

Accepted

### An efficient way to translate a triple for-loop from Matlab to Mathematica

Okay, let's focus on this snippet: ...

### The Lotka-Volterra predator-prey model

The dimensional phase-space plot The analysis of the predator-prey model is incomplete without the phase-space plot. So, here it is, ...

### For Loop and Sum

Anyone asking you to write For loops in Mathematica for such a problem is a dolt. Nevertheless, here's how you might do that: ...
Accepted

### Particle moving on curve which is the intersection of a surface and a plane

You can use MeshFunctions to visualize the intersection. The following is one way to parametrize curve. ...

### How to plot trajectories of the Rossler System

You could try NDSolve then ParametricPlot3D ...

### Area of volume of revolution

r = ParametricRegion[{r Cos[ϕ], Sin[ϕ] r, Sqrt[28 r]}, {{r, 0, 21}, {ϕ, 0, 2 π}}] Area[r] 49/2 π (14 Sqrt - ArcSinh[...

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### Plotting the solutions of $y' = -\frac{\cos y}{\sin x}$

This is just a suggested amendment to JasonB's answer. It wasn't clear to me that it deserves a separate answer, since it deals with side issues tangentially related to the OP's question. It's easier ...

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Accepted

### Plotting Graph of Zeno paradoxes

You'll learn more trying to understand the following code than by programming silly Do[ ]s ...
Accepted

### Exercise using Sort

Using your code, let me make it clear by introducing an auxiliary function that sums the exponents in an expression ...

### Plotting the solutions of $y' = -\frac{\cos y}{\sin x}$

I may not be understanding the question correctly, but if you wish to show the stream field under solutions, perhaps this is a method: ...

### How can I make a pretzel shape using Bézier curves?

You can use a LocatorPane to edit the control points (at least in 2 dimensions) and see the curve change in real time: ...
Accepted

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Accepted

### Strange determinant result

Det[{{0, 1/v, 0, -k12/v^2}, {0, 0, 0, -1/v^2}, {k12, k01, 0, 0}, {1, 1, 1, 0}}] (* k12/v^3*) Laplace ...

### How to check whether Laguerre polynomials are orthogonal?

Integrate[LaguerreL[i, x] LaguerreL[j, x] Exp[-x], {x, 0, Infinity}, Assumptions -> Element[{i, j}, Integers] && j > i > 0] 0 ...

### Euler's method initial value problem — how should I plot the solution?

Euler's method to solve, plot, and compare to known solution: $y^\prime = te^{3t}-2y, \quad y(0)=0, \quad 0 \le t \le 1.$ ...

### Adams-Bashforth method implementation code review

There are typos in the code, and after minor correction we have ...

### Check homework integration in Mathematica

As noted, Boole[] is the go-to method for older versions of Mathematica. Now, thanks to version 10's support for regions, one can easily enter ...
Accepted

### Poisson point distribution

This question was largely dealt with in the comments. I post this for illustrative purposes (but mainly fun): The following shows use of PoissonProcess and its use ...
Accepted

### Use Select to filter a dataset's sublists

dataq[Select[AnyTrue[#c, EvenQ] &]]
Accepted

### Numerical approximation using trapezoidal formula

The error for the trapezoidal rule is So in your case: ...

### Implicitly defined curve

First find the y values like Carl Woll proposed. ...
Accepted

### Rationalize number

Use Minimize with a condition that avoids the divergence to $-\infty$: Minimize[{f[x], x > 5}, x] {(-5 + 2 Sqrt +...
Accepted

### Area of volume of revolution

It seems that f[x] is evaluating to a number. Probably you Set an OwnValues for ...
Accepted

### Infinite While loop

The crux of the matter is how n is changed on each iteration. Math Consider a multi-digit integer $n = a_1 a_2 a_3 \ldots a_N$, where $a_k$ is the $k$-th digit of ...