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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1answer
48 views

Help with linear function, I think

In Argentine, the cost of kW/h is $4,5$ cents and in Latin America, $16$ ctvs (average). a) In how many months would you update the cost to reach $16$ cents kW/h, applying a linear $20\%$ increment ...
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1answer
28 views

can someone help with this graphing math question?

The diagram shows the line $2y=x+5$ and the curve $y=x^2-4x+7$, which intersects the points A and B. How do you find the $x$-coordinates and also the equation of the tangent to the curve at B?
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3answers
127 views

Graph of $(\sin x)^x$

How can you plot the graph for the function $(\sin x)^x$? My problem is that $\sin(x)$ can assume negative values too, so it is not like a standard exponential function. Any help would be appreciated. ...
2
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3answers
60 views

Find the coefficients $a, b, c$ and $d$ so that the curve shown in the accompanying figure is the graph of the equation.

Find the coefficients $a, b, c$ and $d$ so that the curve shown in the accompanying figure is the graph of the equation $y = ax^3 + bx^2 + cx + d$. I have no clue how to solve this. This looks like ...
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1answer
18 views

Filling between two curves in Mathematica [closed]

I want to fill region between 2 curves, but in mathematica 8.0 FilledListPlot[list1, list2, Fills -> {RGBColor[f, f, f]}] doesn't work. can someone help me? Thx
2
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3answers
42 views

Having trouble graphing circles and semi circles

I was asked to graph $y = \sqrt{1-x^2}$. How do I do that? I tried to do a table of values but that did not turn out correct Is their a trick to graphing circles, semi circles, hyperbolas etc
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1answer
28 views

How can I plot $(x^2+y^2+z^2)^2 \leq x^2+y^2$?

if I use spherical coordinates $x=r\sin(a)\cos(b), y=r\sin(a)\sin(b), z=r\cos(a)$, where $a$ goes from 0 to $\pi$ and $b$ from 0 to $2\pi$ I get the following $r^4\leq r^2\sin(a)^2$ $r^2\leq ...
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0answers
35 views

Calculating Eigenvector Centrality & Betweenness Centrality formulas explained in simple terms

I'm currently working on a software application that has a function that analyses networks of people and the relationships between them. Two of the important variables we look at are Eigenvector ...
2
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0answers
37 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: $$ ...
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12answers
2k views

How to explain the perpendicularity of two lines to a High School student?

Today I was teaching my friend from High School about linear functions. One of the exercises we had to do was finding equations of perpendicular and parallel lines. Explaining parallel equations was ...
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0answers
28 views

I was wondering if there was a way to plot a vector field and a 3d surface in the same window

I want to plot the vector field $$\textbf{F}(x, y, z) = \sin(xyz)\textbf{ i }+ x^2y\textbf{ j }+ z^2e^{x/5}\textbf{ k }$$ And the surface (part of elliptic cylinder) $$\textbf{r}(u, v) = u\textbf{ i ...
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vote
3answers
46 views

Why rotating a function around line $y=x$ gives an inverse of this function?

So I'm trying to read through a book on calculus on my own and there is a statement that if we have a graph of some function $y=f(x)$ and this is an injective function, then rotating it around the ...
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0answers
29 views

Graphing inequalities, elementary geometry (Highschool level)

I am going through some past papers, and one of the few questions I need help with are: For the second one, relating to plotting the square root of 4 - $x^2$, I did a table of values starting ...
1
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1answer
39 views

How to trace the graphic of $\cos(x) + \cosh(y) = k$?

Is there some systematic way to trace the graphic of $\cos(x) + \cosh(y) = k$ given a fixed value for $k$? Suppose $k = 1$: if I choose empirically $y = 1.2$, I know that should be $\cos(x) = - ...
0
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1answer
31 views

Sketching the graph of $y =\ln(4-x)$

$y = \ln(4 - x) $ This graph has two operations applied to the $\ln x$ graph - a reflection and a translation. If you reflect the graph in the $y$-axis first, and then shift the graph 4 units to ...
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0answers
21 views

calculate curve based on input data (x, y)

I have a graph that has pre drawn lines drawn on a the graph that indicate the growth rate of their horse. Here is the original graph, this is the only data I have access to. Basically, I want ...
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1answer
22 views

Finding b coefficient by looking at shape of parabolas

I was given the graphs: I was told to say whether the a, b and c coefficients in y=ax^2+bx+c were positive or negative for each graph. The a and c coefficients can be found just by looking at the ...
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0answers
30 views

Identify functions by their graphics

I know it is inprecise, but can anybody suggest analytic functions that fit the following graphics? Here the blue curve is $(\sec x)^2$, need to identify red and yellow. Here the blue curve is ...
4
votes
1answer
47 views

Speediness and correctness when graphing by hand .

First of all thank you for visiting this question! I believe it's a pretty simple problem but get's kinda hairy and time consuming on each step as I have done it, so my question (the one you are here ...
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4answers
75 views

Multiple choice question on rates of change (or so I thought)

If I were to find the resistance of the component (see image below), I would either find the equation of the curve and use differentiation or I'd draw a tangent at $V_2$ and then find the reciprocal ...
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1answer
16 views

Ordering angles using max and min functions

I'm using the awesome Desmos Graphing calculator to graph cyclic quadrilaterals. The idea is that the user can drag a slider to change the value of the angle of each point A, B, C and D. I have done ...
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1answer
30 views

What determines the rotation direction in a $2$ D Dynamical system?

Say we have a non linear system $\dot{x}=f(x)$ and we linearise this around an equilibrium point $x_0$, to obtain the linear sytem: $\dot{x}=Df(x_0)\cdot x$. Where $Df(x_0)$ is the jacobian (and in ...
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1answer
26 views

Can an equation represent a curve in 3D space?

I tried to get a equation that can represent a spiral like spring: $$z=\frac{height}{2\pi }\cdot \arctan \left ( \sqrt{\frac{radius^{2}-x^{2}}{radius^{2}-y^{2}}} \right )$$ I am not sure about the ...
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0answers
30 views

Plot histogram and density function

I need to plot a histogram for the data: ...
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1answer
28 views

Find Sin Function from points?

I have these points and I need to find the sine function can anyone please show me how to do this step by step? Or just give me pointers on where to start and what the equation actually is? (0,2.8) ...
0
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1answer
37 views

what type of function does this curve best represent? [closed]

What type of function does this best represent and also if anyone can help me find that function it would be much appreciated! ! (http://i.gyazo.com/932b96ebf695f259a4301244952aabf3.png) !
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1answer
34 views

Periodic expansion of function

Let $ \tilde{f}: \mathbb{R} \rightarrow \mathbb{R} $ be the 2-periodic expansion of the function $ f: [-1,1[ \rightarrow \mathbb{R} $ given by $ f(x)=x $. But how can I make a graph of $ \tilde{f} $ ...
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0answers
38 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 ...
0
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3answers
148 views

Sketching graphs of circles.

A circle graph function is in the form of $x^2 + y^2 = r^2$ If I am asked to graph $(x-2)^2 + (y - 1)^2 = 4$, do I have to solve for x and y to graph first?
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3answers
67 views

Graph this function: F(x)=$-2^{|x|+1}$.

Graph this function: F(x)=$-2^{|x|+1}$. when I graph this function and go to check by a graphing calculator I find that I am wrong ! even though I do the horizontal translation So, what's wrong? ...
0
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1answer
28 views

How do you visualize the graph of $(x - y)^2 = 4$ without a device?

I can expand it to $x^2 - 2xy + y^2 = 4$, but that doesn't really help, and I cannot isolate the $y$ or $x$ term by itself because of the squared, so I would guess this to be some kind of parabolic ...
0
votes
1answer
39 views

What's a fast way to sketch $y=\sin (5x) + \frac{3}{10}x \sin (5x)$?

What's a fast way to sketch $y= \sin (5x) + \frac{3}{10}x \sin (5x)$ ? I had this question as part of a recent test paper and I had to sketch it for the range $0 \leq x \leq \pi$ . It was for only 2 ...
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2answers
25 views

Region closer to one given point than to any other given point

(Q) *Consider 6 points located at P0=(0,0), P1=(0,4), P2=(4,0), P3=(-2,-2), P4=(3,3), P5=(5,5). Let R be the region consisting of all points in the plane whose distance from P0 is smaller than that ...
0
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1answer
48 views

Function graphs comparison

I'm asking a graph question that has bothered me a while. I'm considering two graphs here: $$ y=(x+2)^2 $$ $$ y=x^2 + 4 $$ As can be seen, both the difference is a mere $4x$. I would like to know if ...
0
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1answer
15 views

How to find last pt of triangle

How to find last pt of triangle. I got (1,7) and (0.5, 4). The equations are y = 3|2x − 1| + 4 and y = −|x − 4| + 10
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1answer
32 views

What does “symmetric about the origin” mean?

What does it mean when a graph or a point on the Cartesian plane is symmetric about the origin or with respect to the origin?
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1answer
25 views

Dissection of strange graph

I want to know why the graph in Strange graph problem looks how it does. Can someone explain? Here's the inequality: $(|x|−1)^2+(|y|−1)^2<2$ You can graph this equation at ...
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1answer
67 views

Describe the graph of f if the graph of its integral its given

Describe the graph of $f$ if the graph of its integral $g(t) = \int_{0}^{t} f(s) ds $ is: graphic of g graphic of f I analyze the derivative and the sign of the derivative and try to find ...
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1answer
26 views

How do you graph a fractal on a line, as a function of time and position?

I'm writing ANSI C code for work and just got working my LED Light Show Library. The first project it's going on is a sound bar with 10 volume indicator (1-color (white)) leds that are lined-up. ...
0
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1answer
24 views

Sketch the graph

Study the derivatives of the function $y={(x^3-4x)^{1\over2}}$ and sketch its graph on the real line. My approach: 1. range of $x$ is $(-2,0)\bigcup (2,\infty)$ 2 . Slope of $f(x)\to\infty$ as ...
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2answers
28 views

$y = xe^{−1/|x|}$ for $−∞ < x < ∞$

(a) Let $f(x) = x − xe^{−1/x}, x > 0$. Show that f(x) is an increasing function on $(0,∞),$ and $\lim_{x→∞} f(x) = 1$. (b) Using part (a) and calculus, sketch the graphs of $y = x−1, y = x, y = x ...
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2answers
28 views

Find the graph of the derivative

The graph of a function $f$ defined on $(0,2)$ with the property $\lim_{x\to 0^+}f(x)=\lim_{x\to 2^-}f(x)=\infty$ is as follows:
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1answer
23 views

Plot a fourier series

I'm not a mathematician but I hope my question is easily answered. I'm trying to learn about graphing equations in a computer application (I'm a programmer). From this link a fourier series is ...
2
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1answer
25 views

Predict the nature of the curve

$$f(x)=\int_0^{\sqrt{x}}e^{u^2\over x}du$$ Hence predict the graph of $f(x)$:
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0answers
50 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 ...
1
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0answers
14 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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votes
5answers
119 views

Points on $(x^2 + y^2)^2 = 2x^2 - 2y^2$ with slope of $1$

Let the curve in the plane defined by the equation: $(x^2 + y^2)^2 = 2x^2 - 2y^2$ How can i graph the curve in the plane and determine the points of the curve where $\frac{dy}{dx} = 1$. My work: ...
2
votes
4answers
96 views

Understanding the graph for $x^y = y^x$

I graphed $x^y=y^x$ and it is a union of the line y=x, with some other curve. So my first question is, how do I derive that other curve? My next question is, why don't I get the same graph when I ...
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1answer
25 views

Mathematics to compare points

I am not sure if this a question for the mathematics stackoverflow or some other. If it is then please move it. Basically, I have a programming challenge where given list of points (which form a line ...
0
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1answer
48 views

Sketching the spectrum of a signal

The figure below shows Fourier spectrum of a signal $g(t)$ Sketch the spectrum of the signal $2g(t)\cos^2(100\pi t)$. Show value in sketch.