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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2answers
64 views

Strange graph problem

I'm trying to figure out this question: in the Cartesian coordinate system, how many grid points (x,y) satisfy $(|x|-1)^2 + (|y|-1)^2 < 2$? When I plugged it in to a graphing calculator, it didn't ...
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3answers
31 views

Graphing a Circle that doesn't have two of each variable

Graph the circle: $$x^2+y^2-2x-15=0$$ I know how to approach this problem if there were two $y$ and $x$ variables. But there is only one $y$ variable. How would I approach this?
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1answer
96 views

How do you minimize “hinge-loss”?

A lot of material on the web regarding Loss functions talk about "minimizing the Hinge Loss". However, nobody actually explains it, or at least gives some example. The best material I found is here ...
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0answers
34 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. ...
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1answer
25 views

Curve Sketching - transforming f(x) to f(a-x)

In class I learnt that to sketch $y=f(a-x)$ given a graph of $y=f(x)$, you reflect the given graph about the line $x=a/2$ (this was proven to us). And then the teacher said that something we ...
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1answer
66 views

Is there closed form for $(1-p)(1-p^2)(1-p^3)…$ or its Taylor expansion?

I was considering the following problem: Somebody uses a backup for something (e.g. backups a file) and the backup is equally reliable as original storage. The storage is not perfectly reliable and ...
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0answers
6 views

Steps in Anlaysing Surface Plot

I have two vectors ${\bf x}$, ${\bf y}$ such that $0 \leq x_i, y_j \leq 1$ and a third vector ${\bf z}$ where $z_i \in \{0,1\}$. Each row of the vectors represents an 'observation' and I am trying to ...
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3answers
62 views

Find the locus of points

Find the locus of points, the distance between them and the point $(2,1)$ is equal to the distance between them and the straight line $4x = 3y$ I know that it is the definition of a parabola But I ...
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2answers
56 views

What is graph of graph of $y = (x-1)\sqrt{x}$

The book "A student's Guide to Fourier Transforms" 3rd edition, by J.F.James, published by C.U.P., on pages 20 and 21 quotes the equation $y = (x-1)\sqrt{x}$ as an example of one that does not meet ...
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0answers
35 views

How do I convert a function $f(x)$ to $f(\frac{x}{a})$?

I have a pretty simple problem but I kinda am confused. I have the function $$f(x)_a = \sqrt{\frac{2}{\pi}} \cdot \frac{Aa}{x^2 + a^2}$$ And especially: $$f(x=0)_a = \sqrt{\frac{2}{\pi}}\cdot ...
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2answers
41 views

creating graphs in wolfram alpha

I am trying to plot the function $$\max(x-40,0)$$ in Wolfram|Alpha, but I can't figure out how. What Wolfram|Alpha query URL should I use to produce this graph? Or, what similar online program could ...
2
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1answer
26 views

Sine Graphs Equation Meaning

What do each of these numbers mean in this equation for sine graphs? y = -3sin[2(x-30)] + 1 I know 1 = shift up What does the rest mean? thanks.
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0answers
18 views

Interpreting functions of graphs

The question asked which of the following is false. I narrowed it down to two, and the correct answer is E with it doesn't cross the x-axis at all. D. f(x) * g(x) intersect the x-axis three times E. ...
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1answer
28 views

Drawing a graph of $x\cos\left(\frac 1x\right)$

I have been given a question which asks to draw the graph of $x\cos\left(\frac 1x\right)$ without a calculator. However, I'm unsure as to how to do this. It may involve differentiation as that was the ...
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2answers
13 views

Scale 'priority' where 1 is larger than 3 for graph

I simply want change a scale on graph so that 1 is largest value and three is smallest. I have data in excel. A function would preferred as I do not want to simply swap the values.
2
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2answers
46 views

Problem with powers

I hope this has not been asked already. while reading a material on upper bounds of polynomials (time complexity) they compared growth of various polynomial functions (like $N\log N$, $N^2$, $N^3$, ...
1
vote
1answer
32 views

description of the function whose graph corresponds to Figure

Consider f be a real continuous function , $f(0) = 0$ , and whose graph has the form shown in the figure: a) How can a give description of the function whose graph corresponds to Figure. b) Sketch ...
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1answer
30 views

Graphing $f(x)=\log7(x-7)-4$ [closed]

Could someone help me get started on this problem? Graph function $f(x)=\log7(x-7)-4$. Show at least two points and dash in any asymptotes. I'm not quite understanding how to find points with ...
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0answers
17 views

Trouble calculating surface area

I am trying to calculate the surface area of a solid of revolution of f(x) about the x axis for the interval [1,6] $f(x) = \begin{cases} 1 & 1 \leq x< 2\\ 1/2 & 2 \leq x< 3\\ . ...
0
votes
1answer
28 views

Finding surface area of revolution

Can anyone help me with finding the surface area of a solid of revolution of f(x) about the x axis for the interval [1,6]. It's supposed to be able to be done without needing calculus but I am having ...
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1answer
50 views

Finding volume of the solid of revolution?

Can anyone help me with finding the volume of a solid of revolution of f(x) about the x axis for the interval [1,6]. It's supposed to be able to be done without needing calculus but I am having ...
0
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1answer
70 views

Drawing polar graphs when given theta in terms of the radius

I know how to plot when it is like $r=10 \cdot \sin(2\theta)$. But how to do that when the condition is like: $\theta =2 \pi \cdot \sin(r)$?
0
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1answer
40 views

Problem with graphing a function.

To my understanding, function $f(x)=\frac{1+x}{1+x^3}$ should not be defined with $x=-1$ since: $f(-1)=\frac{1+(-1)}{1+(-1)^3}=\frac{1+(-1)}{1+(-1)}=\frac{0}{0}$ However, Google's plot drawer and ...
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1answer
30 views

What is the domain of $Z=\sin(\ln(x\,\arccos{y}))$?

What is the domain of $Z=\sin(\ln(x\,\arccos{y}))$? I see that is should be $-\dfrac{\pi}{2}\leq \ln(x\,\arccos{y}) \leq \dfrac{\pi}{2}$ and then $e^{-\dfrac{\pi}{2}} \leq x*\arccos(y) \leq ...
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3answers
36 views

What is the domain of $z=\arcsin\dfrac{x}{y}$?

I get that it should be $|y|>|x|$ and in the Wolfram it looks like this. But when I graph it by hand is that it should be only the "upper" part of intersection and not the "bottom" part as well, ...
0
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1answer
22 views

Finding solutions using graph

Find the number of solutions of the equation $$|\ln|x|\;|=\sin(\pi x)$$ I know how to draw roughly the graph of $|\ln|x|\;|$. However, at $x=1$, both the graphs will pass through $(1,0)$. How do I ...
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2answers
40 views

How to plot not only the result but also the derivatives of an ode using the ode45 function in Matlab?

I have already successfully run a code for the simulation of the deflection of beams under different loadings. I used the Matlab program and the ode45 solver for Initial value Problems and bvp4c ...
0
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1answer
53 views

Plotting 0-360 degrees

I have some direction (bearing from north) data in degrees. Some of this data jumps between 1-360 degrees when plotted as a line graph, which is not easy to read, as the variation is actually only 1 ...
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0answers
39 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 ...
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3answers
65 views

Plotting a region in $3D$ space

I would like to know if someone knows of a software where I can plot the following region $$ D = \{ (x,y,z) \in \mathbb{R}^3: 0 \leq x \leq 1 , \; x^2 \leq y \leq x, \; \; 0 \leq z \leq x \} $$ ...
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1answer
58 views

Matlab Cropping Plots

I want to adjust the amount of whitespace that is shown when plots are generated. I found this command to do just that: ...
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2answers
86 views

Roots of $x^4-3x^2+x-\sin x$

Is there a logical/qualitative argument to find out the number of roots of $x^4-3x^2+x-\sin x$ ? I tried plotting graphs for $x^4-3x^2+x$ and $\sin x$ to check the points of intersection but it only ...
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0answers
13 views

Question on Cobweb Diagram

Let f be a real map and assume that the points a and b form a limit cycle of order two of f. Derive a simple formula for the derivative of the second iterate of f at a.
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1answer
28 views

Choosing values for octave/decade scale

I am developing a frequency response simulator for linear circuits which should be able to plot graphs of Voltage x Frequency with the latest varying linearly, in octaves or in decades. The only ...
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2answers
49 views

Curve stretching

Let $f(x) = x^2$ Let's try to transform that to $8x^2$. First question, is this a vertical stretch scale factor $8$? That would be $8f(x)$ then? But, could it also be $f(\frac{x}{\sqrt{8}})$ because ...
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1answer
56 views

How to draw contour lines (projections) on axis x or y with octave?

With the builtin function contour(x,y,z) of octave one can draw level curves where z remains constant. My question is how to draw contour lines on axis x or axis ...
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2answers
47 views

How do you shift a sigmoidal curve to the right?

How do you shift the function $1$ $/ ( 1 + e ^ {-x} )$ to the right without altering the shape of the curve?
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4answers
48 views

Equation of a line

I've been practising some past previous exam question and came across this: How would you find the equation of the line with y-intercept? -$\frac{3}{4}$ and slope -$\frac{1}{2}$?
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1answer
26 views

How does one interpret, geometrically, $\frac{dx}{dt}>0$, $\frac{dx}{dt}<0$ and $\frac{dy}{dt}>0$, $\frac{dy}{dt}<0$?

I'm specifically referring to this example from my lecture notes: I understand, algebraically, what's going on, but what does the fact that, for example, $\frac{dx}{dt}>0$ and ...
0
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2answers
30 views

Finding the Asymptote / Root of a reciprocal function

$$y = \frac{3}{8x - 3} $$ The y-intercept is $-1$ and the vertical asymptote is $x = \frac{3}{8}$ but what would be the horizontal asymptote and the x-intercept in this case? I am asking this as the ...
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1answer
22 views

Functions (Finding Inverse)

$f(x) = x^2 + 2x$ , domain ${x ≥ 1}$ Question: find the inverse The inverse is $f(x) = 1 + \sqrt(1+x)$ (taking the positive square root only) As $f^{-1}(5) = 2$ and as 2 is an element from the ...
0
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1answer
12 views

Functions inverse + domain

Question part a): !([http://imgur.com/sKJbFKu]) Answer: !http://imgur.com/jRfeXkW Can anyone explain why the inverse must be the negative square root?
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0answers
23 views

How can I visualize the following region

surface $z = xy$ inside the cylinder $x^2 + y^2 = 1$ I took level curves for $z=xy$ when $z=-2, z=-1, z=0, z=1, z=2$, and I got two parallel lines $y=0,x=0$, when $z=0$, and various hyperbolas for ...
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3answers
46 views

Functions definition + question

Am I correct in saying that for Functions, the below is the correct definition: For each value of x in the domain there is only one value of y in the range. Hence, the picture below means that it is ...
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1answer
48 views

Four Square and Eight Promblem

Please help-this problem is pretty difficult for me for some reason.
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1answer
42 views

How to find the number of solutions of $3^x + 4^x + 5 ^x = 6^x$

My try: I tried plotting the graph(manually) of LHS and RHS but it does not give any information whether they will intersect or not.If they will intersect then there will be 1 solution and if they do ...
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2answers
25 views

Symmetry of product of symmetric functions

Let's say we have three functions, $f(x), g(x) \text{ and }h(x)=f(x)\cdot g(x)$, all of which are defined for $x \in [-1,1]$. If $f(x) \text{ and }g(x)$ are symmetric around the y-axis, will $h(x)$ ...
0
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1answer
41 views

Partial derivatives and functions equal to 0

If I have the function (family of curves) $$F(x,y,p)=(px)^2+p=0$$ I am under the impression that $$\frac{\partial F(x,y,p)}{\partial p}=2px^2+1$$ Is not always equal to $0$. Please could you ...
0
votes
1answer
13 views

Comparing two quantities

So I have two agents that have strategies, each of which are specified via one parameter. For agent1 its p and agent2 its q. Each of these agents produce a payoff p1 and p2, which depend on the ...
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1answer
42 views

Equation of a nasty graph

Let $f(x)$ be a real valued diffrentiable function in its domain. Let $PQ$ be a line which is inclined at an angle of $k$ with the tangent of the graph $f(x)$ at $x_0$. The rate of change of the ...