1
vote
2answers
179 views

Finding intersection and graphing [duplicate]

1) How do I find the intersection of f[c_] := y^2 - 2 x^2 (x + 3) == c ((y + 1)^2 (y + 9) - x^2) between the plots of f[0] and f[2] I tried plugging-in numbers. ...
0
votes
1answer
136 views

Count intersections of two non-polynomial functions [duplicate]

I have two Bessel functions, and I need to be able to count the number of intersections if both functions are plotted dependent upon the same variable. I can use FindRoot or FindInstance to get one ...
0
votes
1answer
41 views

finding the coordinates of intersection point of two complicated implicit function [duplicate]

I have two complicated functions and i plot the contours of them like this: ContourPlot[{f[x,y]==0,g[x,y]==0},{x,x1,x2},{y,y1,y2}] I would like to find ...
0
votes
0answers
48 views

Why does NSolve not solve this system of equations on a bounded domain? [duplicate]

I have three functions $E1,E2,E3$ of $t1$ and $t2$. The expressions are slightly complicated and involve trigonometric functions. For clarity purpose, they are given at the end of the question. I wan'...
33
votes
8answers
7k views

About multi-root search in Mathematica for transcendental equations

I have some questions for multiroot search for transcendental equations. Is there any clever solution to find all the roots for a transcendental equation in a specific range? Perhaps ...
24
votes
6answers
7k views

Finding the intersection of a curve with an interpolation function

There are no issues trying to find the intersection points of two defined curves. ...
38
votes
3answers
3k views

Identifying critical points/lines of 2/3D image/cubes

Upshot I am interested in identifying critical points of a 3D field/cubes (maxima, minima, tube-like and wall-like saddle points) and 2D field/image (maxima, minima, saddle points). I.e. the ...
7
votes
6answers
806 views

Finding where two parametric paths cross?

I have been looking through other parametric equations questions and am still unsure where to start with this one. I am given two functions: ...
11
votes
3answers
951 views

Finding “Maxima” and “Minima” on a B-Spline

I need to find the "Maxima" and "Minima" on a B-Spline or more correct the points where the 2nd components of the derivate equal zero. For example: ...
7
votes
3answers
1k views

Finding all maxima and minima of a function

To find all (global and local) extrema of a function in $\mathbb R^3$, I have written the following. Example function: ...
9
votes
3answers
537 views

Using NSolve in the complex plane

I am trying to find numerical values for $\Im\ e^{\frac{1}{2} +i\ y} = \Im\ \zeta(\frac{1}{2} +i\ y)$ for a given range. I have tried: ...
14
votes
1answer
1k views

How do I find all the solutions of three simultaneous equations within a given box?

Sometimes, one needs to find all the solutions of three simultaneous nonlinear equations in three unknowns $$\begin{align*}f(x,y,z)&=0\\g(x,y,z)&=0\\h(x,y,z)&=0\end{align*}$$ within a ...
5
votes
3answers
230 views

How to get the coordinates of the intersection of two lines from a ListLinePlot?

Suppose I have two curves intersect at some point, how can I read the coordinates from the graph, not read by eye, but find it with more precision by computer. For example, here are two lists created ...
9
votes
2answers
1k views

RootSearch for complex or multiple equations

First the background. I'm trying to solve for the roots of a rather messy complex equation. This is not the exact equation, but it's a decent (simpler) stand in: ...
2
votes
1answer
1k views

FindMaxValue and FindMaximum - how to find GLOBAL maximum and not just LOCAL maximum

I will not be able to provide a simple minimum working example here as this seems to be very specific. I have an interpolating function which I substituted into a PDE and then plot said PDE at a ...

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