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.
189
questions
29
votes
4answers
20k views
Finding unit tangent, normal, and binormal vectors for a given r(t)
For my Calc III class, I need to find $T(t), N(t)$, and $B(t)$ for $t=1, 2$, and $-1$, given $r(t)=\{t,t^2,t^3\}$.
I've got Mathematica, but I've never used it before and I'm not sure how to coerce ...
12
votes
8answers
4k views
How to make a resizable chess board?
For some reason I need to create a chess board. I can create a chess board by following command:
...
8
votes
4answers
728 views
Generating a polynomial that's accurate to within an error of no more than 1/10^5
I'm currently stuck on a question for class that asks...
"Find a polynomial p[x] that you can use to calculate
6 ArcTan[x]
to ...
8
votes
2answers
554 views
Check homework integration in Mathematica
Given in my homework I have to compute (by hand)
$$\iint\limits_{x^2+y^2\leq 1}(x^2+y^2)\,\mathrm dx\,\,\mathrm dy.$$
My solution so far:
Let $f(x,y)=x^2+y^2$ and $K=\{(x,y)\in\mathbb{R}^2:x^2+y^2\leq ...
8
votes
3answers
9k views
I want to draw a graph using a weighted Adjacency matrix
I have a weighted adjacency matrix as follows:
...
6
votes
1answer
107 views
NumericQ exercise in Wagner
I've been thinking about this exercise in Wagner (p. 269), but I can't answer. Can you tell me?
5
votes
1answer
468 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, ...
5
votes
1answer
300 views
PearsonChiSquareTest: set degrees of freedom
How to set degrees of freedom for PearsonChiSquareTest?
I have this:
...
5
votes
1answer
2k views
How to plot the solution of a Partial Differential Equation?
My attempt.
I need to solve numerically the Complex Ginzburg-Laudau Equation (CGLE):
$$ \frac{\partial A}{\partial t}=\epsilon A-(1+i\beta)|A|^2A+(1+i\alpha)\nabla^2A $$
I'm using a uniform initial ...
4
votes
4answers
6k views
The Lotka-Volterra predator-prey model
I have a Mathematica assignment where we need to numerically solve a Lotka-Volterra predator-prey population equations.
$$\frac{dx}{dt}=ax-bxy,\quad\frac{dy}{dt}=-cx+dxy,$$
where $a,b,c,d\in\mathbb{R}...
4
votes
3answers
506 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 $...
4
votes
2answers
234 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. ...
4
votes
2answers
287 views
Strange determinant result
I carried out the determinant of a $4\times4$ matrix in two different ways: with Laplace and without Laplace (see this attachment please).
The Laplace's rule is applied "manually" in Mathematica (I ...
4
votes
1answer
267 views
Particle moving on curve which is the intersection of a surface and a plane
Surface
z = 2 x^3 - 5 y^4
Plane
z = x + y + 5
Plot
A curve is formed by the intersection of the surface and the plane.
I ...
4
votes
3answers
347 views
Dot products and For-loops
I'm taking a class where we're working with matrix applications inside of Mathematica. In this case, we're analyzing senatorial votes that have been numericized so that a value of 1 corresponds to "...
4
votes
2answers
199 views
Use Select to filter a dataset's sublists
In the following Dataset, I want to use Select to display only rows, which contain numbers in column ...
4
votes
1answer
464 views
How can I make a pretzel shape using Bézier curves?
I am trying to make a pretzel shape,but I cannot seem to get the loops even.
Eventually, I need to make the pretzel shape loop in 3D so I need to nail the 2D concept first. Here's what I have so far....
4
votes
1answer
93 views
Dynamics problem [closed]
This is school work. I do not want the problem solved for me, but I just want to know what I did wrong with my ParametricPlot.
Question:
A material point moves ...
4
votes
3answers
438 views
Minimizing Multiple Functions
I'm trying to write a script that will minimize a given set of functions. The homework problem I've been given lists a set of dietary information, and I'm supposed to build the optimal salad based on ...
4
votes
1answer
191 views
3
votes
2answers
389 views
Plotting the solutions of $y' = -\frac{\cos y}{\sin x}$
I struggle with the problem of plotting the solution of this ODE:
$\qquad y' = -\frac{\cos y}{\sin x}$
I've already tried to use ContourPlot in a loop and in a ...
3
votes
2answers
754 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
...
3
votes
2answers
267 views
Exercise using Sort
I have to order the following list according to the sum of the powers of each element of the list, using the function Sort.
...
3
votes
4answers
470 views
Print all numbers from a sequence which don't contain the digit 7
so i have this:
Cases[RecurrenceTable[{a[n + 1] == 7 a[n] + n, a[1] == 1}, a, {n, 7}], Except[7]]
But i noticed that it will only exclude numbers that are 7, and ...
3
votes
3answers
159 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 ...
3
votes
1answer
153 views
How do I plot a Laplace transform?
I have been looking everywhere for help on this issue and cannot find a solution that works. Here is the assignment.
I have figured out how to find the Laplace transform, but I do not know how to ...
3
votes
4answers
199 views
Implicitly defined curve
Consider the curve $C$ defined by the equation $y\, \sin(x)+x\, \sin(y)+x+y=0$.
Find all points of the form $(8,y)$ that lie on $C$.
For each point found in part 1, evaluate the derivative $dy/dx$...
3
votes
2answers
144 views
3
votes
1answer
301 views
Using single replacement rule to convert algebraic expression
I have been trying this problems for hours and cannot find any helpful clues.
How can I convert $Sinh[3\theta]+Sinh[\theta]$ to a rational function of x given $2Sinh[\theta] = x-x^{-1}$ by using only ...
3
votes
1answer
146 views
Tower of Hanoi list of disks on the rods
I'm currently trying to finish a program that outputs the "radius" of each disk on each rod in lists. I currently wrote this program:
...
3
votes
1answer
116 views
UnitStep in Mathematica when t varies differently
How can I use the UnitStep command when I have a piecewise function $f(t)$, where $f(t)= 0$, when $|t|>4$, and $f(t)=1$, when $|t|<4$? I tried with ...
3
votes
1answer
271 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
1answer
240 views
Formatting ANOVA table and/or ParameterTable without using Grid?
Does anyone know if there is an option or function that can automatically format the output of ANOVATable and ParameterTable, ...
3
votes
0answers
61 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'...
3
votes
0answers
150 views
Writing a function to set up and solve the least squares problem
I have setup the explicit line equation for a given set of points using least-squares approximation and the knots computed below. I have tried extending the same code for use with an arbitrary degree, ...
2
votes
3answers
2k views
draw part of parabola using graphics
Today, I was doing my physics homework. One of the questions was to draw velocity-time and position-time graphs from the acceleration-time graph. So for the first step I draw acceleration-time using <...
2
votes
1answer
1k views
Using triangulation
I have been presented with 3 known points and the power densities at those points. I need to use those points to find the location of the actual antenna which is generating the signals.
Power ...
2
votes
3answers
989 views
Write program to check if an integer is divisible by 2, 3 and 5 [closed]
Write a program to check if an integer is divisible by either 2, 3 or 5. If an integer is divisible more than one of these numbers it should also show all of them.
For example:
8 is divisible by ...
2
votes
2answers
2k views
Using the epsilon tensor in Mathematica
I'm having a great deal of trouble getting started on a weekly homework assignment in Mathematica. The assignment requires we use the epsilon tensor which is apparently built into Mathematica as ...
2
votes
3answers
406 views
2
votes
2answers
792 views
Plot: 2D potential vortex embedded in 2D uniform flow
Consider a 2D potential vortex (having velocity $u_\theta = c/r$ in a quiescent environment) embedded in a 2D uniform flow (having a velocity of $u_x= U$ far away from the vortex) as below:
Question: ...
2
votes
2answers
429 views
local variable naming & symbolic argument
I'm stuck here with my variable assignment in this scenario
...
2
votes
2answers
166 views
Euler's method initial value problem — how should I plot the solution?
We are given the following initial value problem:
$\qquad y' = t\,e^{3\,t} -2\,y, \quad 0 \le t \le 1, \quad y(0)=0$
Use Euler`s method to approximate the solution to this initial value problem. In ...
2
votes
3answers
193 views
Finding primes that have certain property
Let S[p] denote the sum of digits of p. A prime p is said to be stubborn if none of ...
2
votes
2answers
93 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:
<...
2
votes
3answers
1k views
Parametric Curves Tangent Line
Find an equation to the tangent of the curve at the given point. Then graph the curve and the tangent.
$$x=t^2-t,\quad y=t^2+t+1; \quad(0,3)$$
I can do this with a simple $f(X)$ function but the ...
2
votes
2answers
83 views
Inserting an integer into a list while maintaining descending order
Define a function g with two arguments, w and n, where w ...
2
votes
1answer
298 views
Plotting and ContourPlot
Make a Plot and a ContourPlot that gives the same diagram and use ContourPlot on a quadruple ...
2
votes
2answers
1k views
Using RegionPlot3D to make a cone under restrictions
I have to plot a cone that satisfies this statement:
Use the RegionPlot3D command to draw a picture of a cone with its
point at the origin. The other end of the cone is a circle with
radius 5 ...
2
votes
1answer
543 views
Getting the 557th element of a table
Make a table with elements $\sin(\sqrt{8 n}/4) + r\, $for $n$ from $1$ to $1000$, where $r$ is a random real number between $-0.1$ and $0.1$ that is different for each value of $n$. Also make a plot ...
