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Questions tagged [homework]

Homework questions are welcome, as long as they are asked honestly, explain the problem, and show sufficient effort. Please do not use this as the only tag for a question. Please do not add this tag to questions by other people unless they explicitly say that their question is part of their homework.

-3
votes
0answers
30 views

max heap implementation as an array [closed]

assume that a max heap is implemented as an array.The core of the "percolate down" procedure swaps a node and its smaller child if the smaller child is is less than the node.Write a program function ...
1
vote
1answer
65 views

Drawing an approximate visualization of an inequality using ArrayPlot

I need to write a function that returns graphic visualization of the two-dimensional figure described with equation: $\qquad P = \{(x, y) \in R^2: 4+2x < x^2+y^2<9\}$ I have to use the n x n ...
0
votes
0answers
39 views

Finding tangents and curvature of a parametric curve in 3D [duplicate]

I am in a calculus 3 class and cannot figure out how to get Mathematica to solve for unit tangent, normal tangent, binormal tangent, and curvature without getting a supper messy result. This is the ...
0
votes
1answer
58 views

Monte Carlo simulation using modified rejection technique

Plot the probability density function $\qquad w(x)=(1/(1+x^2))(1/x^{0.5})$ for $(0 < x < 1)$ Make up the subroutine flowchart to get the random numbers $x$, using the modified ...
3
votes
2answers
372 views

For Loop and Sum

I am requested to do a sum of the first fifty positive even numbers by using For loop. The For loop that I created is ...
0
votes
1answer
78 views

Interval determination with mathematica [closed]

I am given the solution y=yo/(1-yo x^2). If yo>0, the solution is valid only on ( -1/sqrt(yo), 1/sqrt(yo) ). How is this determined? I need a proof like answer and I need it programmed in ...
0
votes
1answer
46 views

Creating matrices using a Do-loop

Here is an image of current assignment; I am not able to do step 6 to 8 When I try to do the Do-loop, it states that the {i, j} does not have appropriate bounds. ...
1
vote
1answer
28 views

Why are these arrows not plotting?

I'm very new to mathematica, so pardon me for such a simple question. I have tried to follow the syntax of the "Arrow" documentation(https://reference.wolfram.com/language/ref/Arrow.html), but I ...
1
vote
2answers
61 views

How can I make an arrow's shaft more visible?

{Graphics[{Arrowheads[.1], Arrow[{{0, 0}, {2, 1}}]}], Graphics[{Arrowheads[.1], Arrow[BezierCurve[{{0, 0}, {1, 1}, {2, 0}}]]}]} say I have the above code. Can I ...
0
votes
1answer
61 views

Make Arrows Smaller

I have the following program that describes a 3D curve in space with an osculating circle and TNB vectors moving with the curve. The arrows indicating the TNB vectors are way too large making it seem ...
0
votes
0answers
42 views

Devise a compact storage mode

I am writing a code for solving a symmetric band matrix by Cholesky decomposition. I need to store the matrix by defining only the non-zero diagonals of the matrix not the full matrix with band size $...
0
votes
1answer
88 views

How do I plot x as a function of y?

I am new to mathematica so this might so this might be a silly question. Im in cal 2 and im doing this problem: Use cylindrical shells method to find volume of revolution of region bounded by x = ...
1
vote
3answers
145 views

Another way to calculate frequency from Fourier transform

I have some trouble with calculating frequency after Fourier transform. My code: ...
0
votes
1answer
46 views

How to write a command that produces such a matrix that takes n as an argument, where every node has probability 1/m [closed]

Please help in answering the questions above on mathematica. Which commands do I use to answer the question?
0
votes
1answer
56 views

Solving system of equations for coordinates

This is my first time here, so let me know if there's something I need to add to the post etc. Anyway, I need some help with Mathematica and linear algebra, and I got some tips that this would be the ...
3
votes
0answers
49 views

Plotting gradient and newton directions for parametric system of nonlinear ODEs

I have a bucket (system) of chemical kinetics models, a nonlinear dynamical system given by: where kf >= 0 and kr >= 0 are the parameters. The initial conditions are A(0) = B(0) = 1 and C(0) = 0. I'...
0
votes
1answer
246 views

Translating the Newton-Raphson method from Matlab to Mathematica

I am trying to optimize the variables of two (or three depending on how you think about it) matrices using the Newton-Raphson Method. I made the bottom code in Matlab. The code is pretty simple it ...
4
votes
2answers
195 views

How to check whether Laguerre polynomials are orthogonal?

I've got the problem with checking if Laguerre polynomials for n=1,...,10 are orthogonal. I have to create the list of these polynomials, then create the matrix of integrals from 0 to infinity. ...
-2
votes
1answer
89 views

How can I plot a surface in cylindrical coordinates? [closed]

The surface I want to plot is $z^2 + r^2 = 25\, \theta$. Please tell me how to do it in Mathematica.
0
votes
0answers
61 views

Application of ODE

I got to do some assignment for my Student Research. 1. Cat and mouse are in room which is shape in sqare . Cat is in one topic square, mouse in another one. In topic square oposite than cat position ...
-4
votes
2answers
64 views

Basic Supply and Demand Question [closed]

Suppose that the quantity supplied S and the quantity demanded D for the price p of t-shirts are given by the following functions S(p) = −800 + 50p D(p) = 1900−40p Determine the prices for ...
5
votes
1answer
446 views

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

This is my first post on StackExchange, so if I violate any etiquettes, I apologize in advance. I am a senior engineering student who has been using Mathematica for a year now. For one of my classes, ...
2
votes
1answer
131 views

Analyze stability of equilibria using Routh-Hurwitz conditions

For an assignment, I need to analyze the stability of a system very close to equilibrium, using "Routh-Hurwitz conditions". I have already obtained the characteristic equation of my system, but I do ...
0
votes
1answer
85 views

Simulating the motion of the Earth around the sun based on Kepler’s laws

I am using Mathematica 10.3. I want fo perform a computational analysis of the motion of the Earth around the sun based on Kepler’s laws. Here is my code so far. ...
0
votes
1answer
76 views

Solve won't return an answer for a set of four equations

So I was doing my homework and this system popped up, so I was trying to solve it but Mathematica has just been stuck with it for two days. It won't give me an answer. I am trying to get the code to ...
3
votes
1answer
185 views

Newton's Method

Problem statement: I'm currently new to Mathematica and have been trying to solve this problem. I was digging around and found this code: ...
3
votes
3answers
129 views

Infinite While loop

I have an exercise where I need to input a multi-digit number and evaluate the square of the sum of its digits. I am new to Mathematica and I can't figure out why I'm getting an infinite loop. This is ...
0
votes
1answer
58 views

Solving and plotting a linear initial value problem [closed]

As my first Mathematica assignment, I need to solve and then plot a linear IVP. I understand that I must use DSolve. However, when attempting to plot my output, ...
0
votes
0answers
55 views

Frequencies for Fourier coefficients [duplicate]

I have been given the task of calculating the frequencies to which the fourier coefficients correspond. So my input is a discrete signal [1,4,0,1], which gives me <...
1
vote
1answer
156 views

Using a numerical solver to solve a system of ODEs [closed]

Consider the competition model defined by dx/dt = x (2 − 0.4 x − 0.3 y) dy/dt = y (1 − 0.1 y − 0.3 x) Where the population x(t) and y(t) are measured in the thousands and t in years. Use a ...
2
votes
2answers
60 views

Need help in dealing with messages from Solve and Reduce [closed]

I have a two part question, I am trying to solve what should be a very straightforward equation, but I keep getting messages. Here is the equation ...
0
votes
2answers
110 views

Creating a CDF file from a Manipulate expression

I have created a code in Wolfram Mathematica. I want it to be CDF file. I selected File-> CDF Export -> Standalone. I was told that the file doesn't work but I don't know why. ...
1
vote
4answers
84 views

Contourplot, how to make a circular area?

I am trying to illustrate this math problem with a graph. I tried several things, amongst other: ...
2
votes
2answers
82 views

Illustrate homework (integral region with implicit region)

I must integrate: $$ \int \int_D x^2y^2 dx dy$$ in the first quadrant. This is a triangle with vertices in $(0,0)$, $(0,1)$ and $(1,0)$. I tried to draw it in mathematica with implicit region: <...
0
votes
2answers
80 views

Double integral [closed]

I am trying to use mathematica to verify a math problem which is a double integral: $$\int \int_D (3x+4)^4 \delta x\delta y$$ with $$0 \leq x \leq 4, 0 \leq y \leq 4,$$ I tried the following: -...
0
votes
1answer
36 views

Drawing function that rotates around y-axis with coordinate transform

At last I solved a math problem and trying to illustrate it in Mathematica TO NOT FORGET. I used that code. I works and I get a cake-form. But I think it's missing a big $x$ and a big $y$ axis in the ...
4
votes
3answers
499 views

Area of volume of revolution

I want to calculate the exact area of this volume: RevolutionPlot3D[ f[x_] = Sqrt[28 x] , {x, 0, 21} , Axes -> True ] Additionally, I wish to see $x$ and $...
0
votes
1answer
41 views

Rationalize number

I must calculate the critical point on the function f[x_] := (x^2 - Abs[x - 10])/(x - 5) After plotting, I looked for the minimum where it looked to be (around ...
0
votes
1answer
82 views

Trying to generate random even number

I am trying to generate a random even number, and then try to write the list of primes that are composing it as Goldbach conjecture says. It's just a test to learn how to use mathematica, so I would ...
0
votes
0answers
43 views

Creating a 3D version of the rule 90 cellular automaton

I need help. I want to create a 3D version of the rule 90 cellular automaton, but I don't know how to do it. Please help me. It is for a class in the theory of chaos. this is my code ...
1
vote
2answers
99 views

Solve trig equation

I have a simple trig equation: Clear[f, x] f[x_] = Cos[2*x] - 3 Sin[x] + 2 Solve[f[x] == 0, x] I received a very long a complicated reply that I do not ...
1
vote
1answer
82 views

For what values of $k$ is matrix invertible

I want to know what value $k$ can not be for the matrix A = {{4, 0, 2}, {-1, 2, 0}, {3, 1 , k}} to have an inverse (be invertible). I now you use the ...
0
votes
0answers
42 views

Making Integrals without using mathematics own integral tool. Using rectangle formula [duplicate]

When determined integrals ∫ab f (x) dx become too difficult (almost all in practice) to determine exactly, remains numerical integration. We will look at the simplest, namely the rectangle formula. ...
0
votes
2answers
94 views

What is p[a] for [closed]

I am reading instructions for test on Monday, and I the example below: ...
0
votes
1answer
62 views

Convergent matrix

I had a question where they ask me if a matrix is convergent. Matrix is as below: A = {{-1.7, -12.6, -12.6}, {-1.2, -5.6, -6.6}, {1.5, 7.8, 8.8}} I put it in ...
0
votes
1answer
68 views

How to use Fit with exponential functions? [closed]

"Use Fit to find the fourth degree polynomial that matches best the function $y=e^x$ at the points that have x-coordinates: -2, -1, 0, 1, 2." What I tried: ...
0
votes
2answers
112 views

Calculate area of a triangle

I have another problem that I can't figure out. A triangle har 2 of its summits in points (7.788,0,1.95), (0,7.788,1.95), and the last one on the curve with all the points (7.788,7.788,a^2+1.95), a ...
1
vote
3answers
131 views

Create a plane equation from a point and a line (not normal) [closed]

I have to decide the plane equation in normal form, that goes through the point (3.08,1,4.76) and the line (4.08,3.08,5.76)+ t( 3,6,-3). I have no idea how to do it. I google it and found some ...
0
votes
2answers
154 views

Trig function graphing exercise [closed]

I am trying to figure out how to do the following exercise in Mathematica Graph $y(t)= a \cos t + b \sin t - 0.5 \sin t$ on the interval $0 ≤ t ≤ 6\, π$
0
votes
1answer
68 views

Plot the curve into the xz plane with time interval

At time t ≥ 0, a new laser rocket is at the position: ...