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

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1answer
18 views

What is this graphed function with asymptotes at π/2 and -π/2?

I've come across this function with asymptotes at π/2 and -π/2, which crosses the axis at y=1. It doesn't seem to be polynomial or exponential—can anyone figure out what it is? The asymptotes and ...
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3answers
34 views

How to make a semicircle graph?

What is the formula to make a semicircle graph that is continuous? By continuous I mean like a sine or cos graph but shaped like semicircles one after the other. Thanks
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0answers
11 views

How to calculate a time estimate and plot it?

I recently made a website for a game's community. The game basically has an online dragon which people can fight. Each fight chips off a little bit health. On the next encounter with the dragon, ...
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2answers
45 views

Find the Equation of [on hold]

Hi, Can someone help me to find the equation of this graph.I can find equation of parabolas and cubics individually but don't know where should i start.I know This graph can go to the 3rd polynomial ...
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0answers
15 views

Homogeneity of $f(x,y) = \frac{3x^2y}{x^2+y^2}$

Regarding my previous question about the function $f(x,y)$ somebody claimed that $f(ax,ay)=af(x,y)$ is only true for "homogeneous" $x$ and $y$. Does anyone know what "homogeneous" means in this ...
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1answer
21 views

How to find $x$-intercept on TI-83/TI-84 calculator without having to set the bounds for each intercept?

Finding $y$-intercepts is very easy on a TI-83/TI-84 calculator. All you have to do is graph the function and use 2nd $\to$ ...
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0answers
68 views

The domain of $\frac{\ln x}{x}$.

I have to find the domain for $f(x) = \frac{\ln x}{x}$ Naturally, $x$ must be larger than $0$ and $x$ can't be $0$ so $x > 0$. But when I graphed the function, it has two "parts", one in the ...
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2answers
1k views

What does “versus” mean in the context of a graph?

Say you have a graph of say $y=mx+b$, with $x$ on the horizontal axis and $y$ on the vertical axis. You need to give the graph a title, would you say: This is a graph of "$y$ versus $x$?" or This ...
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1answer
42 views

CALCULUS: Sketching a function by given conditions [on hold]

Pls help. I'm currently on a struggle with this calculus problem. Thanks in advance.
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3answers
25 views

The decision boundary found by your classifier?

Can someone please explain in terms of "How To" find the decision boundary found by your classifier? If I plot using Octave: plot(theta); I get nothing like I ...
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0answers
22 views

Help with understanding when Log(z^k)=k Log(z) as well as drawing the function.

For the question I'm dealing with the property Log(z^k)=k*Log(z)in which I have to find the largest open set that this property is true when $k$ is a positive integer. I understand that this ...
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1answer
16 views

Graph of the same function represented differently?!

I'm taking pre-calculus classes - learning about functions, limits and that stuff right now - and I came to $y = \sin(\frac{1}{x})$. Google represents it like this: Google_graph_of_$y = ...
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0answers
12 views

Determining function of Graph

Looking through some notes on numerical computation I came across the following graph: I know this is a longshot, but I'm not incredibly mathsy and would like to know what kind of a function this ...
2
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1answer
22 views

Drawing critical points together with a level curve

I would like some help sketching the critical points of a given function. The function $f$ is given by $f (x, y) = (\sin x + \sin y)^2$ for all $(x, y)$ in $\mathbb R^2$. The critical points we have ...
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2answers
452 views

Intersection of a point and absolute value function contained within a circle

I'm attempting some crazy ideas while programming a game and ran into the following math problem that has been bugging me for a few days: Given a unit circle and a random point $P$ within the circle, ...
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2answers
36 views

Physics Velocity Correction

So, been up all night working on getting the velocity/angle of arrow simulations perfect. Running into an issue with the physics engine I'm using is ever so slightly off (probably a rounding issue) ...
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0answers
39 views

What would cause the following graph?

I was playing around with a graphing calculator (like you do) and found an interesting graph of $\frac{x}{2^x}$. I was curious if any natural phenomenon that cause a graph to look like that, or if ...
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1answer
48 views

Graph of $f(x,y) = \frac{3x^2 y}{x^2+y^2}$ near the origin

I am trying to graph the function $f : (x,y) \mapsto \frac{3x^2 y}{x^2+y^2}$ on a TI-89 Titanium. I have noticed that no matter how many times I zoom in toward the origin the graph appears identical. ...
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0answers
19 views

Class Scatter Fitness Function Calculation

I get a fitness function for class scatter, the equation: Click here to see the Fitness Function Where : T = Transpose of Matrics Mi = class mean Mo = grand mean The equation is based from ...
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3answers
50 views

Can you inverse a funcion by rotating it?

In school i sometimes run on some excercises where you need to calculate something that has an inverse function in it but you cannot find the inverse and you need to work your way around it. I know ...
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0answers
17 views

Transforming parts of functions

I have a function in the form: $$ \mathrm{e}^{-t\lambda} \cdot \left[t\lambda - {(t\lambda)^2 \over 2}\right] $$ If one were to plot this for say $\lambda = \frac{2}{3}$ and $t$ from $0$ to $20$, ...
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2answers
53 views

Can every one variable equation be solved without graphing? [closed]

Can every one variable equation be solved without graphing? How would you solve the following without graphing: $$3y + 4\sqrt{1-y^2} = 2$$
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0answers
18 views

How to analyse data set

I have a data set from work I'm not sure how to analyse. We have a bunch of people we've contacted (about $1,000$) at a random time during a project they're conducting. That time is expressed as a ...
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3answers
54 views

Show that $\frac{1}{1+k}=\frac{\frac{1}{k}}{1+\frac{1}{k}}\leq \ln(1+\frac{1}{k})\leq\frac{1}{k}$

Prove the following: $$\frac{1}{1+k}=\frac{\frac{1}{k}}{1+\frac{1}{k}}\leq \ln(1+\frac{1}{k})\leq\frac{1}{k}$$ I know I can prove it with induction if the values were naturals. However, the "problem" ...
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2answers
34 views

Functions and Graphs assumption of same algebra equation.

$$f(x) =\frac{ (x - 1) }{(x^2 - 1)}$$ $$g(x) = \frac{1}{(x + 1)}$$ Is $f = g$? why? Solution: answer is no. I don't get it. why can't it be same when it is the alt form?? Can anyone explain this ...
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1answer
955 views

Plotting power-law fit in cumulative distribution function plots

In "Power-law Distributions in Empirical Data", the authors give several examples of alleged power-laws. For instance, they plot node degree distribution of the Internet like this (p. 24): where ...
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1answer
14 views

Assigning functions with graphs easily

Can someone help me with assigning functions with corresponding graphs? How should one proceed to make it easily without a ton of calculations (this kind of exercise I need to do within 5 minutes)? ...
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1answer
78 views

Where are the points of $\{z^{z}\in \mathbb{R}|z\in\mathbb{C}\}$?

I was curious to find out when, given $z_1,z_2\in \mathbb{C}$, I have that $z_1^{z_2}\in \mathbb{R}$ or $z_1^{z_2}\in \mathbb{I}$, where $\mathbb{I}$ is the set of imaginary numbers. So I used the ...
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1answer
28 views

Geometric Meaning behind the algorithm (slope of the line + ray casting)

I'm trying to dissect the classic algorithm for finding if a point is inside a (simple) polygon. Please see: http://erich.realtimerendering.com/ptinpoly/ and ...
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1answer
12 views

Can you stretch a function with a zero or undefined gradient?

If $y=f(x)$ is either $y=3$ (zero gradient) or $x=2$ (undefined gradient), is it possible to stretch $y=f(x)$ by graphing $y=af(x)$ or $y=f(ax)$? If it is possible to stretch them, can you only ...
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2answers
23 views

A circular paraboloid can be a elliptic paraboloid?

I'm aware of this similiar question: what is the difference between an elliptical and circular paraboloid? (3D) But I need help in a different way. In my calculus exam, I was asked to name the ...
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1answer
30 views

Find inflection points of a function $f(x)=\frac{|x+3|}{\sqrt{x^2+1}}$

For $x\ge -3\Rightarrow f''(x)=\dfrac{3(2x^2-x-1)}{(x^2+1)^{\frac{5}{2}}}$ $2x^2-x-1=0$ for $x=-\frac{1}{2}\ge -3$ and $x=1\ge -3$ For $x< -3\Rightarrow ...
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0answers
37 views

How can I plot the complex function in 2D?

My function: $$sin(wt-jT) \tag{1}$$ where $j$ - complex unit, $T=0.1,\ w=8 \pi,\ t=[0,0.01,0.02..100]$ I transform it to function with real arguments: $$\sin(wt)\cosh(T)+j\cos(wt)\sinh(T) ...
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0answers
11 views

Function representing learning review graph

I've been working on this for a while but am unable to get it right. (If anyone is curious, I'm trying to make a model that determines a user's best time to review something that he has studied, this ...
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1answer
35 views

New SAT Math Section: Comparing Equation of Line to Graph

This is a math question on a practice test for the New SAT that will come out in March. These questions should not go above the level of precalc. I'm posting a picture of the problem as well because ...
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5answers
76 views

How to plot the graph of function $f(x) = \sqrt{8\sin^2x+4\cos^2x-8\sin{x}\cos{x}}$?

How to plot the graph of function $$f(x) = \sqrt{8\sin^2x+4\cos^2x-8\sin{x}\cos{x}}$$ Is it even possible ? When I tried it the function compressed into $$f(x) = 2\sqrt{\sin^2x-2\sin{x}\cos{x}+1}$$ ...
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1answer
26 views

Triple Simultaneous Equations not resolving the Equation for a Quadratic Function

so I'm doing this math problem for my Calculus I course in college. Here is a screenshot of the problem: Graph 1 (click here to view); the prompt is "Find an expression for the quadratic function ...
2
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1answer
44 views

What does the double vertical lines in the domain of a function mean?

In my math textbook there was a question to sketch a possible graph in which it gave me some information on it. One of the questions gave me the domain and range of the function. The domain was ...
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3answers
57 views

Is this quadratic pointing up or down? How do I know?

The equation is $-2x^2 + 4x + 30 = 0$. I simplified it to $-2(x^2 - 2x - 15)$. To know if it points up, I need to look at $ax^2$, and if $a > 0$ it is up and if $a$ is $< 0$ it is down. ...
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0answers
19 views

From current plot $y=f(x)$ get plot $dx/dy$ vs $y$

I have a plot $y = f(x)$ where $y$ is voltage and $x$ is capacity. Now I want get from this graph the $dx/dy$ vs $y$ plot. How can I get this new graph?
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1answer
31 views

The inequality used to study a trigonometric function's sign has no solutions

The function, sign of which we are asked to study, is: $$f(x) = 2\sin(x)\cos(x) - 1,$$ or, simplified: $$f(x) = \sin(2x)-1,$$ without using its graph to do so, since the exercise itself asks, in ...
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1answer
695 views

Plotting discrete time signals involving sumations in matlab.

Many of the examples I've encountered while looking for an answer are simple functions that do not involve summations. Suppose I have the following function; ...
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0answers
14 views

How to plot sinusoidal waves of color frequencies?

I'm looking for a function that I can use to plot a sinusoidal wave for various color frequencies. For example, the frequency of red light is 4.6 THz (4.6*10^14 Hz). The frequency of blue light is 6.3 ...
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2answers
44 views

Complex Numbers: How do I know which plane to use?

I'm new to complex numbers and I want to know precisely when I need to use which plane for graphing and a general idea of what the plot would look like. $$z=a+bi$$ When it's in the form above, I ...
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1answer
29 views

Plotting the graph of $\operatorname{Re}(z)<2$

$$\operatorname{Re}(z)<2$$ My idea was that, in the complex plane, the graph looks like a ray starting at the origin and extending up to $2$, but not including that point. Then there would have to ...
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1answer
415 views

Best program for creating educational math animations?

I'm looking for recommendations on what program to use for creating mathematical animations. These animations will be used in creating educational videos for high school math -- Trigonometry first, ...
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0answers
10 views

How can I obtain the equation of a complex signal such as ones obtained from analysing serial buses?

This is an example of a signal I would like to analyse For my mathematics internal assessment, I am trying to apply the Fourier Transform and put a signal through it in order to analyse it and ...
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1answer
3k views

Linear Programming: Three variable graphical solution

A small bank offers three type of loans: housing loans at $8.50$% interest, education loans at $13.75$% interest rates, and loans to senior citizens at $12.25$% interest. Further, it needs to ...
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1answer
34 views

Calculate curve using 3 points

I'm trying to find a way of creating a curve using 3 points in x,y space so I can use it to find other points. Essentially I have a unit which moves up and down on the y axis and I want to be able to ...
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3answers
45 views

How do I graph Linear Programming questions?

So let's say I have the following constraints: $2a + 3b \leq 30$ $a + b \leq 15$ $a \geq 0$ $b \geq 0$ (I just made this problem up, so I'm not sure if it may make any sense when I graph it.) ...