Questions regarding calculators such as the TI-83 (Plus), HP 50g, and other calculator models.

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29
votes
4answers
12k views

Calculator algorithms

Does there exist a good reference on the algorithms used by calculators, especially on the trigonometric and transcendental functions? I would still like to know how Casio generates its random ...
21
votes
7answers
2k views

“Why do I always get 1 when I keep hitting the square root button on my calculator?”

I asked myself this question when I was a young boy playing around with the calculator. Today, I think I know the answer, but I'm not sure whether I'd be able to explain it to a child or layman ...
6
votes
7answers
1k views

How calculators do trigonometry [duplicate]

I need to use a calculator to find trigonometric ratios like $\sin(41),\cos(32)$. How do calculators work for trigonometry? Also, as calculators are invented by the human mind can we do it mentally? ...
6
votes
3answers
1k views

What is the definition of $2.5!$? (2.5 factorial)

I was messing around with my TI-84 Plus Silver Edition calculator and discovered that it will actually give me values when taking the factorial of any number $n/2$ where $n$ is any integer greater ...
2
votes
2answers
267 views

In my calculator why does $\sqrt4 -2=-8.1648465955514287168521180122928e-39?$

I have tried this on my Windows 7 calculator with $\sqrt9 -3 $ it too gives some weird answer- ie$1.1546388020691628168216106791278e-37$. And so for any $n$(positive) $\sqrt n^2-n= wierd_ .answer$ Why ...
2
votes
1answer
297 views

Negative × Negative = Positive… right?

The wife and I were doing homework together, and we noticed something really strange when charting quadratics with a TI-series graphing calculator: ...
0
votes
1answer
2k views

Subtraction of numbers with arbitrary bases [duplicate]

Possible Duplicate: How to do +, -, *, / with number in a base b? I am reading research papers in the category of recreational mathematics on the topic of numbers similar to Kaprekar ...
1
vote
2answers
4k views

Calculate on which side of straign line is dot located

I am a programmer without really good knowledge in math. :/ So I have to write an algorithm that changes the color of pixel(dot) P to opposite if it's on left side of the straigt line in coordinate ...
0
votes
2answers
1k views

How do calculators handle $\pi$?

When the calculator displays the digits of $\pi$, how does it arrive at that answer? Also, at what digit does the approximation of $\pi$ stop at?
10
votes
4answers
3k views

How do pocket calculators calculate exponents?

I'd like to know specifically how a pocket calculator (TI calculators also apply) calculates $e^{0.1}$, and what methods or algorithms pocket calculators use in order to produce their answer.
2
votes
0answers
267 views

Solving $x$ for $y = x^x$ using a normal scientific calculator (no native Lambert W function)?

Solving $x$ for $y = x^x$ using Lambert W function is clear enough thanks to this handy answer, but as I'm using the solution in a network support document I need it in a form that can be solved on a ...
1
vote
5answers
4k views

How can I evaluate an expression like $\sin(3\pi/2)$ on a calculator and get an answer in terms of $\pi$?

I have an expression like this that I need to evaluate: $$16\sin(2\pi/3)$$ According to my book the answer is $8\sqrt{3}$. However, when I'm using my calculator to get this I get an answer like ...