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https://community.wolfram.com/groups/-/m/t/1568356
I'm currently doing some Mathematica exercises, and I'm stuck on this one task where you're supposed to plot the functions h(t)= |3-t^2|+|t-1|-t^2 , g(t)=3sin(t) in the same grap, and then find all the roots. This is what I've got so far:
![enter image description here][1]
[1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=UHvxo.png&userId=1540567
The instructions say that I should use FindRoot to exactly decide all the roots, but I don't think I've done it right. What should I change with the function in order to make it find all of the roots?
Thanks in advance.Jhn Snd2018-12-09T11:50:45ZSolve the differential equation by Runge Kutta method?
https://community.wolfram.com/groups/-/m/t/1563269
I need to solve the equation as follows by numerical methods such as Runge Kutta, Newton Raphson, ... Hope everyone help me. I thank everyone.
![enter image description here][1]
[1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Untitled.png&userId=1563397Vũ Ngọc Việt Hoàng2018-12-01T15:10:42ZUse NMinimize calling a own defined function with FindRoot?
https://community.wolfram.com/groups/-/m/t/1567276
I defined my own function which solves a transcendental equation by using a findroot, and it works. But, when I call my own defined function with NMinimize, it gives me an error. I do not understand where it comes from. Attached please find my code. Please let me know if you know where the problem might be.Mario Junior Mencagli2018-12-07T05:10:37ZCalculate and plot the roots of a polynomial?
https://community.wolfram.com/groups/-/m/t/1565716
Hi, on mathematica I have represented the following polynomial a * x ^ 4 + b * x ^ 2 + c * x + 2 using the "Plot" command and, through the "Manipulate" command, it is possible to vary the parameters a, b, c. Now, however, I would like the program to give me back the roots of the polynomial according to the parameters a, b, c .... could you help me kindly?
This is the code:
Manipulate[
Plot[a*x^4 + b*x^2 + c*x + 2, {x, -20, 20},
PlotRange -> {{-20, 20}, {-20, 20}}],
{a, -1, 1}, {b, -10, 10}, {c, -10, 10}, ControlPlacement -> Right]Pasquale Rossi2018-12-04T19:00:18ZNonlinear feedback system
https://community.wolfram.com/groups/-/m/t/1564351
I have a set of nonlinear equation which i have solve it by using AffineStateSpaceModel. My code is given below. I have the following query
1.Is it correct to use OutputResponse syntax to find the solution of the AffineStateSpaceModel.
2.I use interpFN to extract each of the output from the solution. Is there any alternative way to extract the solution so that i can plot the graph.
3.And finally I wanted to use If condition as input value which I am unable to do it.
Kindly help me. Thanks in advance
{i1 = 10, i2 = -1, i3 = 0.9, i4 = Abs[Sqrt[1 - i3^2]], mu1 = 1,
mu2 = 0, mu3 = 0}
nsys = AffineStateSpaceModel[{{x3, x4, 0, 0, 0, 0, 0.6 x9, 0.6 x10, 0,
0, 0, 0},
{{0, 0}, {0, 0}, {x5, 0}, {x6, 0}, {-x3, 0}, {-x4, 0}, {0, 0}, {0,
0}, {0, 0.6 x11}, {0, 0.6 x12}, {0, -0.6 x9}, {0, -0.6 x10}},
{x1, x2, x7, x8, x1 - x7, x2 - x8, 0.6 x10 - x4, x3 - 0.6 x9}},
{{x1, i1}, {x2, i2}, {x3, i3}, {x4, i4}, {x5, -i4}, {x6, i3}, {x7,
0}, {x8, 0}, {x9, 1}, {x10, 0}, {x11, 0}, {x12, 1}}]
sol = OutputResponse[nsys,
{-mu1*Dot[
Normalize[{x1[t] - x7[t], x2[t] - x8[t]}], {0.6 x10[t] - x4[t],
x3[t] - 0.6 x9[t]}]
- mu2*
Integrate[
Dot[Normalize[{x1[t] - x7[t], x2[t] - x8[t]}], {0.6 x10[t] -
x4[t], x3[t] - 0.6 x9[t]}], t]
- mu3*
Dot[Normalize[{x1[t] - x7[t],
x2[t] - x8[t]}], {.36 x12[t] Dot[
Normalize[{x1[t] - x7[t], x2[t] - x8[t]}], {-x10[t],
x9[t]}], -.36 x11[t] Dot[
Normalize[{x1[t] - x7[t], x2[t] - x8[t]}], {-x10[t],
x9[t]}]}],
Dot[Normalize[{x1[t] - x7[t], x2[t] - x8[t]}], {-x10[t], x9[t]}]},
{t, 0, 300}];
u1 = interpFN = sol[[1]];
u2 = interpFN = sol[[2]];
u3 = interpFN = sol[[3]];
u4 = interpFN = sol[[4]];
u5 = interpFN = sol[[5]];
u6 = interpFN = sol[[6]];
u7 = interpFN = sol[[7]];
u8 = interpFN = sol[[8]];
ParametricPlot[{{u5, u6}}, {t, 0, 20}, Mesh -> 40,
GridLines -> Automatic]
{ParametricPlot[{{u1, u2}, {u3, u4}}, {t, 0, 15},
PlotLegends -> {"pursuer", "evader"}, Frame -> True,
GridLines -> Automatic, Mesh -> 10],
ParametricPlot[{{u1, u2}, {u3, u4}}, {t, 0, 20},
PlotLegends -> {"pursuer", "evader"}, Frame -> True,
GridLines -> Automatic],
ParametricPlot[{{u1, u2}, {u3, u4}}, {t, 0, 30},
PlotLegends -> {"pursuer", "evader"}, Frame -> True,
GridLines -> Automatic, Mesh -> 30],
ParametricPlot[{{u1, u2}, {u3, u4}}, {t, 0, 300},
PlotLegends -> {"pursuer", "evader"}, Frame -> True,
GridLines -> Automatic]}
r = EuclideanDistance[{u1, u2}, {u3, u4}]
Plot[r, {t, 0, 30}, GridLines -> Automatic, AxesLabel -> {t, "r"}]
gamma = Dot[Normalize[{u5, u6}], Normalize[{u7, u8}]]
Plot[gamma, {t, 0, 30}, GridLines -> Automatic,
AxesLabel -> {t, \[CapitalGamma]}]OBIROY LAIRENJAM2018-12-03T19:11:23ZSolve the Extended Generalized Bivariate Meijer G Function (EGBMGF)?
https://community.wolfram.com/groups/-/m/t/1564744
Hi everyone,
I am currently working on RF/FSO transmission systems. As a solution in the analytic expression, I obtained Extended Generalized Bivariate Meijer G Function (EGBMGF). To my best knowledge, the EGBMGF is not available in standard mathematical packages. How can I solve the problem numerically by using wolfram mathematica? How to calculate EGBMGF in mathematics? I deliver the analytical term of EGBMGF.
![enter image description here][1]
[1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=EGBMGF.jpg&userId=1564710Marko Smilic2018-12-03T13:53:30ZSave output data after solving second order differential equation?
https://community.wolfram.com/groups/-/m/t/1565597
Hello, first time I am using Mathematica, I tried to solve second order coupled differential equation but I don't know how to save the output data from this solution! Would you please help me! Here is my code:
m = 9.1*(10)^(-31)
q = 1.6*(10)^(-19)
Er = 14116.83261708455
Ep = 0
Ez = 4609.405077963418
Br = 0.2226 (10)^(-4)
Bp = 0
Bz = 0.1825*(10)^(-4)
s = NDSolve[{r''[t] - (q/m)* (Er + p'[t] * Bz - z'[t] * Bp) == 0,
p''[t] - (q/m) * (Ep - r'[t] * Bz + z'[t] * Br) == 0,
z''[t] - (q/m)* (Ez + r'[t] * Bp - p'[t] * Br) == 0, r[0] == 0,
r'[0] == 0, p[0] == 0, p'[0] == 0, z[0] == 0.006,
z'[0] == 6.9*(10)^(5)}, {r, p, z}, {t, 0, 10}]
Plot[Evaluate[{r[t], p[t], z[t]} /. s], {t, 0*(10)^(-9),
10*(10)^(-9)}, PlotStyle -> Automatic]
I would like to save the output data of r[t], p[t], z[t], t as a text file. Thanks in advance!Padam Ghimire2018-12-04T14:47:37Z