Questions tagged [calculator]
Questions regarding calculators being used to solve math problems. A clear statement of the math problem to be solved is required.
431
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Hello everyone, I want to ask one calculation, I tried my best , but still cannot find up answer , please help [closed]
$$\lim_{x\to 0}\frac {\arcsin (5x)}{\sin (3x)}$$
I don’t know how to solve this please hlepppp
0
votes
2
answers
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Zero to the power of negative numbers
I lately stumbled unto a strange behaviour of my calculator (a TI-Nspire™ CX II-T CAS):
$$
\begin{split}
0^{-2} = 0^{-4} &= \infty & \forall \text{ even numbers}\\
0^{-1}, 0^{-3} &=...
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1
vote
2
answers
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Does there exist a projective CAS calculator?
I'm sorry if the question isn't strictly related to maths but I really can't seem to find anything good and I don't where to ask.
Just to see some projective curves I thought to search for a Graphic ...
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2
votes
1
answer
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Why did my calculator take this number for $e^x=0$, or better why does he even give a solution? [closed]
My calculator gives a solution to $e^x=0$, this on itself quite strange, but the value is also interesting: $x=-9,9997457056636 \times 10^{98}$. My best guess is that it has to do with the limit of $x$...
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0
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Online calculator for linear algebra complete solution to a system of linear equations
Looking for an online calculator that can provide the complete solution to a system of linear equations $Ax= b$ (given matrix $A_{m\times n}$ and $b\in \mathbb R^m$) as a self-study resource for my ...
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votes
0
answers
31
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Conversion of fractional decimals to binary using a calculator. Why does this work?
When I was doing a math exercise that required me to convert fractional decimals into binary, I noticed that 0.75 and 0.875 had similar binary forms, 0.11 and 0.111 respectively. So one thing lead to ...
2
votes
1
answer
118
views
Why does my TI-84 evaluate this expression involving pi to a whole number?
While working on some homework tonight, I entered the following expression into my TI-84 Plus:
$$\frac{(90×0.006)}{(\pi/4×0.006^4)}$$
I did a double-take when I saw that the output was exactly 530,516,...
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votes
1
answer
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The sum of the probability of an event and its negation is not exactly 1?
the probability of an event is $(1-0.00015)^{16}$ and its negation has probability $16*0.00015-0.00015^{16}$
but their sum is: $1....
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votes
1
answer
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Why Linear regression using Numworks calculator doest give exact result
I tried to do a simple linear regression using the "Numworks" calculator and unless I add many more data points or add a point where x=0 it doesn't give me the correct equation.
Could ...
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votes
1
answer
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How PEMDAS,BODMAS are true in this case [closed]
If we look at this expression
$\frac{A}{B + C}$
It looks like it is simply
$A ÷ B + C$
But the calculator does it as
$A ÷ ( B + C )$
Why does the calculator do it like this as in the first place there ...
0
votes
0
answers
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How to quickly approximate a value
If you had to approximate the value of $\frac{10^6 - 11}{2^{12}}$ quickly and in your head, how would you do it? (The real value is 244.14)
The way I done it on paper was $\frac{10^6 - 11}{2^{12}} \...
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votes
1
answer
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Why is the binomial coefficient button labeled nCr on most calculators?
Most of the time I see the binomial coefficent explained using the variables $n$ and $k$:
$${\binom {n}{k}}={\frac {n!}{k!(n-k)!}}$$
I understand that the C stands ...
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2
votes
1
answer
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Why does the TI-30X Pro calculator seem to get the derivative of $\sin(x)$ at $x=0$ wrong?
I typed the derivative of $\sin(x)$ at $x=0$ into my calculator, and it outputted $0.0174...$ I was expecting the answer $1$. What went wrong?
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Syntax Error when multiplying by a negative number
I just got a new calculator it's the Ti-30X Pro MathPrint. (I belive that it is not sold in the US). When I try to multiply by a negative number, say (-1) to change the mathematical operator I get a ...
user1187463
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1
answer
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How does a calculator calculate binomial coefficients for large $n$?
I've got an interesting puzzle. I'm playing around on a Casio fx-991EX and I notice it has a binomial distribution function. Trying to see how large of a value of $n$ it could take, thinking that in ...
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Randomly pressing buttons of a calculator [closed]
There's a normal scientific calculator with only $12$ buttons: from $0$ to $9$ and $+-$
Randomly press these buttons $n$ times. What will be the math expectation of the result? (Imagine that the ...
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votes
5
answers
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Why is % difference of aggregation higher than individual % differences?
I'm calculation the % difference in completion rate (before vs after) of Product A (0.3%), Product B (16.7%) and the combination of Product A and B (17.0%). I'm unable to explain why the combination ...
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votes
3
answers
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A large discrepancy evaluating $\int_{5.566}^{5.568}\frac{(\sin 6x)^{14}}{(\cos 11x)^{8}}dx$ with Hiper Scientific Calculator vs WolframAlpha
So, in a nutshell, dealing with Hiper Scientific Calculator and Wolframalpha Integral Calculator . Only this integral
$$\int_{5.566}^{5.568}\frac{(\sin 6x)^{14}}{(\cos 11x)^{8}}dx$$
is being strangely ...
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0
votes
0
answers
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Calculating the information entropy of a discrete signal on a calculator
In the last few days I've found myself having to calculate the entropy of a discrete symbol source (which emits one symbol chosen among a finite set with corresponding probabilities). The formula is ...
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votes
1
answer
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Not getting the right derivative of $(x-a)\arctan\frac{(y-b)(z-c)}{(x-a)\sqrt{(x-a)^2+(y-b)^2+(z-c)^2}}$ with respect to $c$
Derivative of:
$$\left(x-a\right)\arctan\left(\dfrac{\left(y-b\right)\left(z-c\right)}{\left(x-a\right)\sqrt{\left(x-a\right)^2+\left(y-b\right)^2+\left(z-c\right)^2}}\right)$$
w.r.t. $c$ is, ...
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Why wolfram alpha is not showing integrand error?
$\tanh^{-1}$ of any real number whose modulus is $1$ or greater than $1$ is meaningless. So the following double integral must be meaningless. But when I computed the following double integral in ...
- 554
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votes
2
answers
364
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What does italic i mean in integral calculator?
In Wolfram Alpha I computed the following double integral:
What does $i$ mean here? Does the result have imaginary part also?
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votes
1
answer
45
views
TI-84 Matrix Fractions Question
Apologies if this isn't the place to ask!
I use a TI-84 CE. When I run the RREF for saved matrices, I often get decimals returned in the output. I'm wondering if there's a way to consistently convert ...
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Diagonalization calculator of definite quadratic forms using the "completing the square" method
In this question: Calculating the maximum value of a quadratic polynomial on several variables with some restrictions, I asked about finding the maximum value of a certain quadratic polynomial with ...
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0
answers
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Testing the the truth of the hyperbolic functions on a calculator.
Test the truth of the formula $\cosh ^2 x-\sinh ^2 x=1$ on a calculator you will probably find that the output changes from 1 to 0 somewhere between $x=10$ and $x=20$. Why is this? Should we conclude ...
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Why can't I compute $(-2)^\frac28$ using a calculator?
Why can't I compute $(-2)^\frac28$ using a calculator?
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Casio fx-100AU COS calculation error
I am calculating the following on my Casio fx-100AU:
7.5cos((2pi/365)*24)+21.5 -> 28.99980502, which is incorrect it should ...
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0
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This is a question about graphing calculators, the TI-84 Plus, etc ones. How do I connect them to my laptop?
All of the videos and information I can find about connecting TI-84 Plus/etc calculators to laptops are outdated. And the only type of cord I can find is this with the end that's too large for my ...
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0
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Computing Multivariable Definite Integral On TI-Nspire
Whenever I try running the following integral on the Ti-Nspire, I get an "undef" error:
integral (0,inf) of x^2 * (1/y)^(-x/y) dx
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initial current and voltage estimate from the equation
There is a paper called [Real Time Hardware-in-Loop Implementation of LLC Resonant Converter at Worst Operating Point Based on Time Domain Analysis][1]
I am trying to derive equations 25 and 26 from ...
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Is it possible to calculate z-score given the probability using a casio calculator?
I have a casio fx-991EX CLASSWIZ calculator and I would like to know if it is possible to calculate the z-score knowing the probability. Every source I found explains the inverse (calculating ...
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Creating an equation that will return a linear result
I am a web developer and I need to create a multiplier between 1 & 10 or as close as possible. I have a variable value that is essentially a date range in days (1 day ago = 1, 10 days ago is 10... ...
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Question on graphing space curves in a plane
This is from Gilbert Strang's Calculus Book, on the section of partial derivatives.
I am not sure at all what this means. How can you graph 3 variables in a TI-81 calculator (which is what I assume ...
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Calculator - Why can I not calculate 7F FF FF FE * 2
I just tried to calculate on my CASIO fx-991 ES the following equation:
$7F FF FF FE_{16} \cdot 2$ and
$7F FF FF FE_{16} + 7F FF FF FE_{16}$
My result was MATH ERROR.
I therefore expected I ...
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votes
0
answers
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Computing log of a number with low precision calculator
Say I have a low-precision calculator that displays numbers with only 8-digits mantissa.
For example, 0.00432137378 would read ...
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1
answer
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How to solve for m in this equation without using the quadratic formula
Tangents drawn from (b,a) to the hyperbola $\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$ makes angles $\theta_1$
$\theta_2$ with the x-axis. If $\tan\theta_1$$\tan\theta_2$
=2 then $b^2-a^2=....$
The equation ...
user1062191
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votes
1
answer
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Distribute percentage of quota % evenly
Let's say I have 65% of a company and my partner has 15% of the same company, so together we both have 80% of the company.
We want to give a new partner 7% of our company, and for that to happen, we'...
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votes
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Why do different calculators disagree on $\cos(452175521116192774 )$?
I want to calculate cosine of 452175521116192774 radians (it is around $4.52\cdot10^{17}$)
Here is what different calculators say:
Wolframalpha
Desmos
Geogebra
Python 3.9 (standard math module)
...
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Calculator Confusion: fractional roots of negative numbers [duplicate]
(Calculator type: Sharp EL-W531)
When I put in the power (-0.2)^(-4/5) it says "calculation error."
Is this not just raising $(-0.2)^{-4}$ then taking the ...
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votes
1
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How do I multiply using this "Addiator"-style calculator?
I've got an old "Addiator"-style calculator (pictured below), but not the instruction manual.
I know how to use it to add (place the stylus next to a digit and pull down, pushing up and ...
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0
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Quickest way to do n/(n+m) on a 4-function calculator
Let's say the problem I want to solve is:
I have n "widgets" and m "doodads". I want to know what percentage of the total items are widgets.
Let's say I only have a basic 4-...
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0
answers
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Why does my calculator say that the cube root of $0$ is "Infinite"?
In all my years, I have known that $0^x = 0\space\space\forall\space\space x \in \mathbb{R}^+ - \{0\}$.
Today, I tried calculating $\sqrt[3]{0}$ on my phone calculator, but I get an unexpected result ...
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2
answers
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Why calculate cos on different calculator get different results?
I just recently start to learn cos. I found out when I use different calculators to calculate cos, sometimes may get different results which is quite confusing.
For example, cos(35), I am calculating ...
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Is $a^x \pmod{n} = (a\pmod{n})^{x \pmod{n}}$? [closed]
Is it right to claim that:
$a^x \pmod{n} = (a \pmod{n})^{x \pmod{n}}$?
I know that:
$a^x \pmod{n} = (a \pmod{n})^{x}$?
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Can anyone figure out the functioning of this Ukranian 1917 pinwheel calculator?
I have bought this online, but cannot for the life of me figure out what it does.
It says "composition" at the top and "reading" at the bottom.
There are columns of numbers with a ...
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0
answers
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is it safe to use Trigonometric of large number in pocket scientific calculator
In this book (from 90s), there is a suggestion to reduce angle interval down to between 0 and 360 degrees, when the angle is larger than $360^\text{o}$ or when the angle is negative.
So here is my ...
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0
answers
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TI 84 Plus CE with Python not able to handle complex polar form in degrees.
I am aware that the TI 84 calculators only allow the angle for complex polar form to be in radians. On my old TI 84 (I just got a new TI 84 Plus CE), I could work around this issue (no matter what ...
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votes
1
answer
920
views
How to compute week and month wise percentage from day wise percentage?
I have day wise participation percentage for a group of customers, for the whole year.
My data is as follows:
Day 1: 100%
Day 2: 50%
Day 3: 0%
Day 4: 12%
Day 5: 2%
and so on till Day 365: 0%
My ...
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votes
1
answer
231
views
Why does Wolfram Alpha give different answers to this algebraic equation depending on how it is entered?
I am trying to solve the equation $Ce^{-\sqrt L t} + De^{\sqrt L t} = Ce^{-\sqrt L (t + 2m\pi)} + De^{\sqrt L (t + 2m\pi)}$ for $L$.
Here Wolfram Alpha returns the solution $m = \frac{in}{\sqrt L}$, ...
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2
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How to calculate the result of a recursive equation?
I'm looking for a tool (like Wolfram Alpha) that can calculate the result of $ B(P,N) $
Where $B(P,N)$ is a recursive function defined as follows:
$
\left\{\begin{matrix}
B(P,N)=\frac{-(-1)^{\frac{N}...
