A service that has several calculators and teaching material for Mathematics, with its most prominent feature being a graphing calculator that is available as an app and on a website.
Questions tagged [desmos]
57 questions
14
votes
1 answer
Why does this desmos plot of the integral of $\sqrt{1+e^x}$ have these discontinuities?
I computed the integral of $\sqrt{1+e^x}$ by hand and got
$$2\sqrt{1+e^x} + \ln\left(\sqrt{1+e^x} - 1\right) - \ln\left(\sqrt{1+e^x} + 1\right) + C,$$
or
$$2\sqrt{1+e^x} + \ln\left(\frac{\left(\sqrt{1+e^x} - 1\right)^2}{e^x}\right) + C.$$
But when I…
Zhiyuan Liu
- 180
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13
votes
1 answer
How to use AND condition in Desmos
Sorry maybe it's not typical mathematics question, but Desmos is very helpful in solving and testing mathematics issues, so maybe anyone could help me.
I can't figure it out how to use AND condition in Desmos
For example to make OR you can just use…
pajczur
- 413
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13
votes
3 answers
Express "if true, then 1 else 0" in a formula suitable for Desmos calculator
In programming, often the value of True is also 1, and False is 0.
This means that:
(x>5)*4
will return 4 if x is greater than 5 (because (x>5)==1), else 0.
I need to accomplish a similar thing using mathematical operators (no piecewise functions,…
theonlygusti
- 1,263
- 2
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7
votes
2 answers
$\frac{\max(1,xy)}{y} = x$: Did I just create a fractal?
https://www.desmos.com/calculator/6hfyqc6ks9
Did I just create a fractal? Again, the function is $\frac{\max(1,xy)}{y} = x$.
Even uncannier version, from the alternative form with "sgn" that Wolfram provided:…
Josh
- 455
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5
votes
1 answer
Ellipse bounded between two lines and a circle
Given two circles with radii $\beta$ and $\beta^{-1}$, where $\beta\geq1$. Also, given two lines $y=x\tan\alpha$ and $y=-x\tan\alpha$, where $\pi/2>\alpha\geq0$. I am interested in all ellipses with center at $(k,0)$ that are bound between these two…
Lee
- 1,870
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4
votes
5 answers
Discrepancy in definite integral $\int_{0}^{2\pi}\frac{1}{10+3\cos x}dx$ using Desmos
I was trying to calculate the following definite integral of a function $f(x)$:
$$\int_{0}^{2\pi}\frac{1}{10+3\cos x}dx$$
After some effort, I managed to find the following antiderivative:
$$F\left(x\right)\ =\…
Zacky
- 41
- 1
4
votes
2 answers
How would one describe $k$ iterations of $\cos(n)$?
What function would one use to describe $k$ iterations of $\cos(n)$? I'm pretty sure that the function would be a damped sine wave (as can be seen in the curve fit equation I wrote in the third row), however the actual formula is probably quite…
Josh
- 455
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4
votes
1 answer
Why ambiguities show up analytically and not graphically?[Limits]
I'm sorry if I sound naive but I have recently studied the topic of limits in high school and didn't understand something.
I understand that we need limits for determining undefined values like $\frac{0}{0}$, ∞/∞ ,1 raised to ∞ etc,but why do we…
Kashi
- 95
- 7
3
votes
0 answers
Error in desmos while computing $\int_{-\infty}^{\infty}e^{-x^2}dx $
When I was computing this integral $\int_{-\infty}^{\infty}e^{-x^2}dx $ on Desmos I was getting correct answer as $\sqrt \pi.$
But when I started to change the limits of the integration something weird started happening
can anyone tell me what is…
Ketan
- 83
- 10
3
votes
1 answer
Why doesn't Desmos Graphing Calculator graph $(-1)^x$?
Shouldn't it at least plot down $(-1)^0$ and $(-1)^1$?
Ninja Nolan
- 33
- 4
3
votes
1 answer
How do I write this basic recursive formula into Desmos?
I want to graph a simple equation $f(x)$ which begins at $(0,1)$, then for every increasing $x$ integer increment, $f(x) = f(x-1) - (c * f(x-1))$.
So in other words each time you go up by one $x$ integer you take the previous $x$ value's $y$ output…
mike
- 349
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- 13
2
votes
2 answers
Is $\frac{x^2-3x-4}{-3x-15}\Big/\frac{x^2-16}{x^2-x-30}$ defined at $x=6$ or not?
If a number is in the denominator of a rational expression that itself is the denominator of another rational expression, such that the number causes the latter denominator to be undefined, then isn't the entire expression undefined?
For example,…
Isaac Sechslingloff
- 361
- 7
2
votes
1 answer
$ \tan{\left\lfloor{x}\right\rfloor}$ self-similar?
As you can see here, there is plenty of what appears to be self-similarity within the graph of $ \tan{\left\lfloor{x}\right\rfloor}$. Every $7\pi$ interval along the x-axis there appears to be a repeating backwards tangent graph made from the…
Josh
- 455
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2
votes
0 answers
Desmos sin wave sum shows different to code
I have followed The Coding Train's Discrete Fourier Transformation series, and added a feature which spits out the coefficients of the equation.
I wrote test in the program, which looked nice. However, when I plugged in the coefficients into Desmos,…
Larry the Llama
- 131
- 5
2
votes
1 answer
In Desmos, function fills entire screen unless $y$ is used in some denominator
In Desmos, I am graphing the equation
$$(g^2 - 4x)y^2 + (2g - 4x - 4)y + 1 = 0$$
which uses the helper function
$$g = x + 1 - \frac{x^2 - 2x + 1}{x + 1 + 2\sqrt x}$$
which fills up the entire screen, even though it should be a smooth curve.…
Prismavoid
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