Questions regarding the plotting or graphing of functions. Questions about graphs with vertices and edges should use the (graph-theory) tag instead. (STUB)

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6
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46 views

Is “imposing” one function onto another ever used in mathematics?

First of all, let me define what I mean by "imposing." Basically, I mean graphing some function with respect to some other function, rather than with respect to the x-axis. To be more specific, for ...
4
votes
0answers
127 views

How do you call functions that fulfill $f(x)=\pm f(\pm 1/x)$?

A function $f(x)$ that fulfills $f(x)=\pm f(-x)$ is called (a)symmetric even/odd. How do you call functions that fulfill $f(x)=\color{blue}\pm f(\color{red}\pm 1/x)$? ...
3
votes
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111 views

Visualising surface integrals

For a current problem I am working on, I have run into angular surface integrals, i.e. the differential solid angle $\text{d}\Omega$. Specifically the surface integrals are defined by ...
3
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0answers
96 views

Graphs of interesting integrals of the form: $\int \sin^a(x^a)\cos^a(x^a)$

Here are a few graphs of the form:- $$\int \sin^a(x^a)\cos^a(x^a)dx$$ Where $a$ is an even, positive integer. $a = 2$ $a = 4$ $a = 6$ Now, a few graphs of the form:- $$\int ...
3
votes
0answers
48 views

Plot implicit equation in sub-quadratic time complexity

It is fairly straightforward to plot an explicit equation such as $y=x^3+3x^2+2x+5$ in linear time, because you can just iterate through all $x$ in your graphing space and use the equation to ...
3
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0answers
72 views

Properties and representations of the the rescaled complementary error function $\mathrm{erfcx}{z}$

Consider the rescaled complementary error function: $$ \mathrm{erfcx}(z) = {e^{z^2}} \left( {1-\mathrm{erf}(z)} \right) $$ $z \in \Bbb{C}$ which also has the following integral representation: $$ ...
3
votes
0answers
50 views

How to approach sketching sine and cosine graphs with transformations

Any tips or suggestions in sketching these graphs quickly, and in ONE go? In exams, I don't want to spend ages re-drawing the original sine/cosine graph, one by one, following each new ...
3
votes
0answers
329 views

Recognizing subadditivity

Let $f: (0,\infty) \to \mathbb{R}$ be some continuous function. We say that $f$ is subadditive if the bound \begin{align} f(x+y) \leq f(x) + f(y) \tag{1} \end{align} holds. I was attempting to ...
3
votes
0answers
184 views

Sketching the graph of a function

How would I sketch the graph of the following function. Sketch the graph of a function satisfying the following conditions $f(1)=2$ $f(-1)=f(3)=-1$ $f'(1)=0$ $f'(x)>0$ for all $x<1$ ...
2
votes
0answers
41 views

Fourier Series of the batman equation

I want to represent the batman equation as a Fourier Series. (I got the equation here : Is this Batman equation for real?) But a part of it is an ellipse and when I tried to calculate an the integral ...
2
votes
0answers
30 views

Graphing the derivative from a graphed function

For the graphs of $f(x)$ make a sketch of the graph $f'(x)$ Here are the sketches I have so far. The graphs on the top row are the original functions. Did I graph these correctly?
2
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0answers
34 views

Why is the graph of 4 nodes and 2 edges not self-complementary?

I am having some trouble seeing why a graph of 4 nodes and 2 edges is not self-complementary such that G is isomorphic to G bar (G complement) (please see the attachment below). I know that the number ...
2
votes
0answers
93 views

Differential Equation Direction field

What i want to achieve: I want to plot the direction fields of the following three differential equations: 1. Malthusian growth model: $p'(t)=\lambda*p(t)$ with $\lambda=1$ and $p(t)=t$ 2. Linear ...
2
votes
0answers
61 views

Is there a way to graphically show that a solution is the minimum or stationary solution to a functional?

I'm looking for the functional analogue to the visual representations of function optimization you most commonly see. To illustrate, if we have some function: $$ f(x) = (x-1)^2+1 $$ We can look at ...
2
votes
0answers
104 views

Math software for plotting phase portraits

I'm looking for math software which is possible to plot phase portraits for ODE and systems of differential equations. Is there a software which can create not only simple 2D phase portrait plots but ...
2
votes
0answers
41 views

Plot histogram and density function

I need to plot a histogram for the data: ...
2
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0answers
56 views

$x^{y}=y^{x}$ Intersection Question

I'm looking at this problem, $x^{y}=y^{x}$ and the question is to find the point of intersection of the two curves that form a solution set. I understand how to find the point of intersection using a ...
2
votes
0answers
70 views

Should a “good” equation divide the plane?

At the question Is there any equation for triangle? (MSE) the answer given by Henning Makholm received the most upvotes. Therefore let's define the following triangle function $H$ with (a,b,c) the ...
2
votes
0answers
67 views

Using Graphs Changes the Solutions for Diophantine Equation? Imperfection of Graph?

Solve the Diophantine equation $$x^2+4y^2=z^2$$ The problem here is that I derived solutions using two different methods, and the both solutions do satisfy the given equation yet they are ...
2
votes
0answers
102 views

how to choose point spacing to approximate a parametric curve using line segments?

Suppose I have a parametric equation for a curve $\vec{r} = f(t)$, which I wish to draw using line segments between some set of points at times $t_0, t_1, t_2,$ etc. If I want to achieve a given ...
2
votes
0answers
275 views

Find a function (curve fitting) for given values

I am trying to assign scores for URLs based on their view counts. I have about 300,000 URLs. In a two-day interval, only 1 URL got more than 5000 views 8 got between 1,000 and 5,000 views about 500 ...
2
votes
0answers
146 views

Ellipse radius interpolation with different radiuses

I am writing a library for graphical LCDs and I want to incorporate a function to draw a circle on the screen. I have already succeeded in drawing simple circles, however, I want to be able to pass a ...
2
votes
0answers
78 views

planarity of graph as a consequence of its flow

Is it possible to distinguish planar and non-planar graphs (networks as a matter of fact) by flows? That is, is there a flow criterion for a graph being planar or not?
2
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0answers
178 views

My solution is right and the book is wrong (parabolas) or did I misunderstand it?

Find the equation of the parabola with the vertex at the origin; directrix 2x = 3 So what I did is, find the equation of the directrix $$x = \frac{3}{2}$$ and then because its the directrix, the ...
2
votes
0answers
259 views

how to obtain state space diagram and state space model for transfer function

How do we obtain the state space diagram and state space model for transfer function for example the question is given How to draw state variable diagram for the given transfer function ...
1
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0answers
40 views

Finding probabilities of a continuous random variable

I have the following continuous random variable density function: $$ f(x) = \begin{cases} \frac14 & if\,0\le x<1 \\ \frac12 & if\,1\le x<2 \\ a & if\,2\le x<4 \\ 0 & ...
1
vote
0answers
22 views

Realistic Bounce (Using Trig?)

background: I am making a graphics program where the major purpose of it is to have a ball (traveling on an arbitrary slope) to bounce realistically off of a line (which is also at a arbitrary slope). ...
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0answers
27 views

How do I find the domain and range of this piecewise defined function?

Are both conditions true when $x>3$? If so, how do I graph it? $$ f(x)=\left\{\begin{aligned} &x^2-4&&:x>3\\ &2x-1&&:x\geq 3 \end{aligned} \right. $$
1
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0answers
40 views

Can trigonometric equations be graphed?

I was solving various trigonometric equations. I was confused that how are they solved easily by using methods that are useful to solve algebraic equations. Do the trigonometric functions in ...
1
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0answers
31 views

Negative option value

I have an exercise where I need to replicate the following graph: with my own parameters. To do this I use: $\begin{align*} \text{Call option value} =SN(d_1)-Ee^{-r(T-t)}N(d_2) \end{align*}$ ...
1
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0answers
26 views

Plot the characteristics for Burgers equation

I'm trying to plot the characteristics for the following problem. So far I have managed to find all the gradients for the lines from each value of x0. But I'm not sure how to plot it. It seems like ...
1
vote
0answers
53 views

Real world application of slanted conics (parabolae especially)

I am writing a report on slanted conics of the form $$(x-h)^2+(y-k)^2= \dfrac{d}{\sqrt h}$$ Where $(h, k)$ is the focus, and $d$ is the directrix. Are there any real world applications for slanted ...
1
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0answers
45 views

Graphing a complicated equation

How do I draw the graph of this equation $p(\theta^{*} (x))\hat{G} - (1-p(\theta^{*} (x)))(\bar{P} - r(x)) = \check{G}$ Here the $\check{G}$ is a positive constant and is a straight line, but how ...
1
vote
0answers
54 views

What function has a 3D graph that will look like a spiral into a singularity?

I am trying to draw text spiraling into a black hole, from a more interesting slightly off-orthogonal viewpoint. I think a function that defines a black hole/singularity surface might look something ...
1
vote
0answers
25 views

Circular node, direction of trajectories?

I have a problem that is a circular node: $\begin{bmatrix}0 & 1 \\ -1 & 0 \end{bmatrix}$ gives $\lambda = \pm1$ It is complex on both, so it is a circular node. Using equilibrium points, we ...
1
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0answers
74 views

Given a function and its transformed graph, find an equation of the transformation

Given a parent function and its transformed graph, I need to find an equation of the transformation. I cant seem to figure #13 or #14... I get confused with which points to start with when dealing ...
1
vote
0answers
41 views

Drawing Phase planes with one input, rather than long scripting

What software can be used to draw phase planes easily? I want to input some $\begin{pmatrix}x_1 \\ x_2\end{pmatrix}=$blahblah, and have it plotted with or without initial conditions. Is there any ...
1
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0answers
36 views

Help with understanding how to sketch a graph of y=1/f(x) and y = xf(x)

I'm having problems trying to figure out how to sketch a graph for these 2 questions. Could someone provide me a step by step guide on how to do this? Thanks in advance.
1
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0answers
33 views

A rectification, what is the graph of the following?

What is the graph of y=y(x) of: $\sqrt {{{(x - 2)}^2} + {y^2}} + \sqrt {{{(x + 2)}^2} + {y^2}} + \sqrt {{x^2} + {{(y + 2)}^2}} = 16$ Thank very much
1
vote
0answers
62 views

What kind of trend, and relationship is this graph?

I need some help with labeling the trend of this graph, and also deciding what the relationship is between the two variables (X,Y). Here is a picture of it: The Excel document can be downloaded ...
1
vote
0answers
50 views

Representing distances in high-dimensional space

I have a set of n points $P_i$ $(i=1..n)$ in an d-dimensional space. I can calculate the distances of every point to each other point. What is the best way to represent the distances of these ...
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0answers
26 views

Is there any interactive spline fitting software?

I'd like to know if there's any software (freeware) for interactive data interpolation. What I want is to be able to visualize my data on an XY plot and drag the points to see how it affects the ...
1
vote
0answers
65 views

Graph of f(x) = the first number in the decimal expansion of x

I'm a bit confused about the answer given in the textbook. I take the definition of 'the first number in the decimal expansion of $x$' to mean simply the first number in its base $10$ ...
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0answers
140 views

Is there a name to this equation: $(y - a|x|^b)^2 + (cx)^2 = d$?

While doing a survey of the various equations that generate the universal love symbol, a heart curve, I find that many fit into this parametrised form: $$(y - a|x|^b)^2 + (cx)^2 = d $$ Where   ...
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0answers
132 views

For which real numbers $c$ is there a straight line that intersects the curve $y = x^4 + 9x^3 + c x^2 + 9x + 4$ in four distinct points?

For which real numbers $c$ is there a straight line that intersects the curve $y = x^4 + 9x^3 + c x^2 + 9x + 4$ in four distinct points? I don't quite the understand the solution which is in ...
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vote
0answers
448 views

How to plot decimals on a line graph?

Trying to plot 56.8, 113.6, 170.4, 227.2 and 284 on the x axis of a line graph, what scale should I use? And should it start at 0?
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vote
0answers
61 views

Quartic Polynomial Manipulation

I have a quartic polynomial in $x$ (too long to write here) $f(x,c_1, c_2, c_2)$ where $c_1, c_2, c_3$ are constants which I have complete freedom over how to fix their values, as long as they are ...
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0answers
43 views

What is the number of x-intercepts in this graph of sine?

The function : $y=3-4\sin(2\pi x-3\pi)$ .. how many $x$-intercepts over the interval $[0,2]$? I am confused if they're 3 or 5 because there are 3 $x$-intercepts that are really intercepting ...
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0answers
17 views

Shape of graph and plot

Suppose $x \in [0, \infty)$ and $y \in [-1,1]$. When we plot $y$ vs. $x$, we get an upward parabola shape. Suppose we plot $y^2$ vs. $x$. Would the shape also be approximately an upward parabola?
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0answers
89 views

How to find change points in a graph on matlab

I have a graph like this I need to find points at which sudden changes happening for the DPC Time Curve. We can observe that at time 20 and around 70 increase is happening. How to do this in Matlab. ...