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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0
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1answer
26 views

How (the graphic of) a $\mathcal C^1$ but not $\mathcal C^2$ function looks like

We know examples of functions (obviously we are in the context of real valued functions) which are continous but not derivable; the simplest is $x\mapsto|x|$. In particular we have a precise graphic ...
2
votes
1answer
22 views

Sketch $ z\in \mathbb{C}:0 < arg(z-(1+i)) < \frac\pi3 $

Sketch the following $$ z\in \mathbb{C}:0 < arg(z-(1+i)) < \frac\pi3 $$ I have considered this geometrically and ended up thinking that the complex numbers $z$ must satisfy $$0 < ...
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2answers
16 views

plotting of level curves using pen and paper

I want to plot the level curve for the function $f(x,y)=\frac{y^2-x^4}{y^2+x^4}$ . I tried by substituting $f(x,y)=k$. But I am Unable to draw it using paper and pen. Kindly help me.
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1answer
21 views

Fitting the data for an given expression [on hold]

I have a set of data's, for which I have to correlate an expression. The data is attached below X Y 0.07195277057274192, 0.00005315407180029256 0.0757623706849068, ...
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0answers
12 views

Displaying a 3D function without a graph

I have a 3D function $z=\dfrac{x}{y}$, and I have no access to a function grapher, but I still need to display this function in a comprehensible way. I thought of a table, but even with a domain of ...
1
vote
1answer
43 views

Find equation of ellipse given two tangent lines at given points and a point on ellipse

I'm attempting to generate an ellipse for a stair simulation game of mine, and the inputs are: A point on the ellipse The slope of the tangent line to the ellipse at that point Another point ...
0
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0answers
31 views

How to read $y = ax^0 + bx^1 + cx^2 + dx^3 + ex^4 + fx^5$

I'm trying to understand how a performance curve control calculates a graph. The manual says "$y = ax^0 + bx^1 + cx^2 + dx^3 + ex^4 + fx^5$" I get that $y$ is the vertical axis, a to f are the ...
1
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1answer
39 views

Integration of a function defined by its graph, the union of semi-circles and a line segment

I don't understand how to do this problem and I would someone to help me with it.Please step by step for me. I just started on integration so this problem is a bit too hard for me due to my lack of ...
1
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3answers
35 views

Easy: Graphs of Straight Line

I can't exactly figure out how to work this out. Well I know the equation for a straight line is $y = mx + c$ $c = gradient$ Therefore if I multiply $3$ by the number $x$ to get the gradient $6$ ...
2
votes
1answer
19 views

how to calculate this logarithmic function?

Im having trouble in graphing this log function: $y=\log _{1/4}\left|x^2-5x+6\right|$ I found the intervals: $(-\infty, 2)$, $(2,3)$, $(3,\infty)$ Should I just give $x$ values and find $y$ to graph ...
0
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0answers
30 views

Slope of the secant line given a point

The point $P(1,0)$ lies on the curve $y= \sin(10\pi/x)$. (a) If $Q$ is the point $(x, \sin(10\pi/x))$, find the slope of the secant line $PQ$ (correct to four decimal places) for $x=2, 1.5, 1.4, 1.3, ...
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0answers
20 views

Get a function (equation) from data points?

Is there a way to get a function (equation) from data points? For example, we have this famous Google's 'Batman' function: ...
2
votes
1answer
34 views

Graphing algorithm

I am not sure if this belongs on Mathematics Stack Exchange, but it is somewhat relavant here. The Problem If you've installed any graphing/plotting apps on your smartphone, you will notice that the ...
0
votes
2answers
16 views

Why $(h,k)$ in equation $y= a(x-h)^2 +k$ is the vertex of a parabola?

As in the title , I know how to convert normal explicit equation to a vertex form equation by completing the square . But what is the reasoning behind why $(h,k)$ must be the vertex , but not other ...
0
votes
2answers
35 views

does anyone know how to graph $x^2+2y^2+3z^2=12$?

I just can't think of how I should draw this graph in 3 dimensions. Can anyone draw a graph for this?
1
vote
1answer
19 views

What will the graph of this parametric equation look like?

What will the graph of this parametric equation look like? $$x = 2t$$ $$y = t + 5, \quad -2 ≤ t ≤ 3$$ Does "$-2 ≤ t ≤ 3$" represent the domain?
2
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0answers
37 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 ...
1
vote
1answer
41 views

How to guess that $f(x,y)$ has no limit?

I need to determine if the limit as $\mathbf{x}\rightarrow \mathbf{0}$ exists for the following functions: ($f:\mathbb{R}^2 - \{(0,0^T)\} \rightarrow \mathbb{R}$) $f(x_1,x_2) = ...
0
votes
1answer
28 views

Draw $-dU(x)/dx$ for $U(x)$

It's been a little while since I've done any problems like this, but I just wanted to make sure I'm on the right track. Updated attempt:
1
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1answer
27 views

Plotting Step Functions - connecting the steps?

How does one choose whether or not to draw vertical lines connecting the steps of a step function? Let's take the cdf of some discrete random variable as an example. My intuition tells me to graph ...
0
votes
1answer
23 views

What is the difference between log scale. and plotting logarithms?

I find plots in scientific literature beyond confusing. I understand quite clearly the difference between a linear and a logarithmic scale, and when each is desirable. Suppose we are plotting values ...
0
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1answer
33 views

I need and equation/graph

I've been out of school for a long time, and don't remember how to do this. I have some points on a graph with a curved line and I'd like to know an equation for them so I can plot beyond what I've ...
4
votes
1answer
57 views

How to make a good “infinity plot”?

This is what I mean (note the labels in the x axis): The reason I'm looking at this problem is because I've always felt something was not right with truncated plots (e.g. of the exponential ...
0
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1answer
23 views

Find constants in expression of the form $y = ax^b$

So I have a real system that for a given setting, x, returns a value, y. These values appear to follow (with some limits) the form of $y = ax^{-b}$ - could also be expressed as $y = \frac{a}{x^b} $. ...
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9answers
1k views

examples of functions with vertical asymptotes in real life

As a math teacher, I tend to get the class involved by finding real-life applications of the math- with functions and vertical asymptotes I am having trouble finding simple enough (rational) functions ...
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1answer
52 views

Analysing the derivatives of a sketched curve

I have the following graph and want to know: Are these statements correct and if not why? question A: $f'(-2) > 0$ question B: $f(0) = 0$ and $f'(0) = 0$ and $f''(0) \neq 0 $ question C: there ...
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0answers
44 views

What is a good book to train drawing graphs of function?

I am about undergraduate here , and I just want to ask what is the best book for drawing graph of functions as I am very weak in drawing graphs
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3answers
34 views

Function graph transformations

I'm looking for a reliable document with formal mathematical justification of how and why graph transformations work. Given a function $f(x)$, what is the graph of $f(a-x)$? Why should we shift $f(x)$ ...
0
votes
1answer
27 views

Plot a set, given in cylindrical coordinates, with Maple and $\text{plot3d}$

I want to plot the set $\phi(A)$ with Maple, where $$\phi:[0,\infty)\times[0,2\pi)\times\mathbb{R}\to\mathbb{R}^3\;,\;\;\;(r,\phi,z)\mapsto(r\cos\phi,r\sin\phi,z)$$ is the transformation in ...
0
votes
2answers
37 views

Graph of $y=\text{constant}*x$

Graph of $y=x$ , $y=\frac{1}{2}x$ and $y=\frac{1}{4}x$ is All are straight line. But with different slope. Why?
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0answers
9 views

Phase difference of two signal of different frequency

Currently, I have two signals, the main components of both signals are 60Hz, but both also have weaker response at 180Hz + small amount of noise. As shown in the photo below, I want to find the phase ...
0
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2answers
15 views

Given a line, calculate a perpendicular line to make a T shape

I am working with SVG vector graphics, and I want to make a dynamic T shape by adding a perpendicular line. I have a line with two points (4,17) and (11,3). How can I figure out (x1,y1) and (x2,y2)? ...
1
vote
2answers
37 views

Graphical representation of complex numbers

How would you graphically represent the following complex functions on the Argand plane (ie. not polar coordinates): $$|2i-z|=|z+1+3i|$$ and $$Re[(3-4i)z]>0$$ I know that $|z-a|=c$ is a circle ...
0
votes
1answer
32 views

How to sketch the level curves of $f(x,y) = x^2 - y^2$

I've been practising functions of several variables for college and I've been working with circles all the time $(x^2 + y^2)$, however, I still can't figure out how to solve non circular shapes, as ...
1
vote
1answer
38 views

Question regarding the graphing of differential equations in grapher (mac)

I am new to grapher (mac) and I am trying to graph Lotka-Volterra equations. For those of you who you do not know, the Lotka-Volterra model is a model that describes the population of two competing ...
0
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1answer
18 views

Variations of a sinc function

Consider the following function \begin{align} G(\omega_t) = \frac{1}{N_t}\text{exp} \bigg( j \pi \Delta_t \omega_t (N_t-1)\bigg) \frac{\sin (\pi N_t \Delta_t \omega_t)}{\sin (\pi\Delta_t ...
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votes
4answers
39 views

Double branch $\sqrt x$ or square function turned 90°?

I have this idea for a graph but don't know what function could describe it better. The idea is something like the "squared" function turned $90$ degrees to the right, so that possible values for $x$ ...
1
vote
1answer
46 views

Exponential function given two points

I am trying to find an exponential function satisfying two points (having base "exp"). After some search, I couldn't find something relative (the most relevant was that ...
0
votes
2answers
49 views

Is $f(x) =|x| - 3$ even, odd, or neither?

$$f(x)=|x|-3$$ Is the function above odd, even or neither? I know that a function is even if $f(x) = f(-x)$: $$f(-x) = |(-x)| - 3$$ $$f(-x) = x-3$$ Does this mean that the function is even? ...
0
votes
1answer
21 views

Solving a curve sketching task

I have some troubles with the general idea of curve sketching. I have following function that I have to sketch. $$ y = \frac{1}{2x^{2} + 12x + 6}. $$ I have the intercepts $y = 1/6$ and no ...
2
votes
1answer
27 views

Locus of line segments

If we take a line segment of infinitesimally small length, and draw another line segment of the same length from the endpoint of the first at a particular angle and repeat this infinite number of ...
0
votes
1answer
43 views

How to plot this complex polynomial?

I have tried using ti-89, ti-nspire and wolfram alpha, but none have given me a plot of this complex polynomial. I admit that I have may not inputted the formula correctly in wolfram alpha. The ...
4
votes
1answer
86 views

Distribution of Rational Numbers on $[0,1]$

If I define the function $$\Phi(n) := \sum_{k=1}^n \phi(k),$$ where $\phi$ is Euler's totient function, and I define $Q_n(x)$ to be the number of distinct rational numbers with demoninators $\leq ...
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0answers
13 views

What is a good graphing software that make me adjust graph on the grid?

I'm looking for a good graphing software where I can drag and adjust graphs on a grid and the software will give me the equation of the adjusted graph?
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0answers
32 views

Sketch $\frac{\sin(x)}{1 + a \cos(x)}$ for “every possible” $a$

I am trying to sketch $$f(x) = \frac{\sin(x)}{1 + a \cos(x)}$$ for every possible $a \in \mathbb{R}$, but I can not find good ranges of a which the function behaves similarly in that specific range. ...
5
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2answers
195 views

How to graph this sin equation?

I have the following sin equation which I am supposed to graph: sin(3x) = -1 and also find how many solutions it contains ...
0
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1answer
43 views

Absolute maximum on $(-\infty, \infty)$, must be local maximum?

I think yes, and I think it must true for any open interval not just $(-\infty, \infty)$ Just wanted confirmation, OR am I wrong
0
votes
1answer
51 views

Splitting up a series of numbers: How to determine when a value increase is significant?

I have 100 input values: $0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
2
votes
2answers
47 views

Plotting a function (by hand) if the second derivative is hard to find

In plotting graphics we use the first derivative to find critical points and in which intervals the function grows and becomes smaller. We can insert the critical points in the second derivative to ...
2
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0answers
52 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 ...