Questions about quadratic formula

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Discussion Overview

The discussion revolves around the quadratic formula and the evaluation of double and triple negatives in the context of randomly generated second-degree equations. Participants explore the implications of defining "random" coefficients and the resulting probabilities of encountering specific sign combinations in the calculations.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • One participant questions the percentage of equations that would yield a double negative for -b and a triple negative for -4ac, seeking a probabilistic approach.
  • Several participants express confusion over the concept of "percent of equations," with some suggesting that the infinite nature of real numbers complicates the question.
  • There is a discussion about defining "random" in the context of coefficients a, b, and c, with some suggesting a uniform distribution of signs.
  • One participant argues that without a specified probability distribution for the coefficients, the original question lacks a definitive answer.
  • Another participant proposes that the signs of a, b, and c could be treated as independent random variables with equal probability for positive and negative values.
  • Some participants suggest that the original inquiry could be better addressed through combinatorial problems rather than probabilistic percentages.
  • One participant attempts to analyze the problem by plotting parameters and discussing the nature of solutions based on the discriminant of the quadratic equation.
  • There is a recognition that the original poster's focus on double and triple negatives may have been overlooked in the broader discussion of parameter distributions.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to define "random" in this context or how to approach the question of percentages related to double and triple negatives. Multiple competing views remain regarding the interpretation of randomness and the implications for the quadratic formula.

Contextual Notes

The discussion highlights limitations in defining randomness for real coefficients and the challenges in applying probabilistic reasoning to an infinite set of equations. There are unresolved mathematical steps regarding the distribution of coefficients and their impact on the evaluation of the quadratic formula.

  • #61
agentredlum said:
You keep saying this, even though I keep correcting you.

I don't use 4 formulas.

I only use 1 formula, the formula that minimizes operations.

You refuse to understand this-Occam's Razor

Ahh, I see. But it only minimizes operations when you have a quadratic in one particular form, correct?


Anyway, I prefer the formula that is derived directly using the definition of a root of a function.
 
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  • #62
agentredlum said:
Many times, in many posts you and others said there was no use for it. Even only as a curiosity it is useful. It has computational advantages as well.

So what are you saying now?

It is trivial but useful?

I can't speak for micromass or anyone else, but my claim is that it is trivial and usless.
 
  • #63
Robert1986 said:
Ahh, I see. But it only minimizes operations when you have a quadratic in one particular form, correct?Anyway, I prefer the formula that is derived directly using the definition of a root of a function.

I NEVER have to compute a double negative for b

I NEVER have to compute a triple negative for +4ac

5 out of 8 times you have problems i don't

Here is a fact about amicable numbers.

In 1636, Fermat found the pair (17296, 18416) and in 1638, Descartes found (9363584, 9437056), although these results were actually rediscoveries of numbers known to Arab mathematicians. By 1747, Euler had found 30 pairs, a number which he later extended to 60. In 1866, 16-year old B.*Nicolò I.*Paganini found the small amicable pair (1184, 1210) which had eluded his more illustrious predecessors (Paganini 1866-1867; Dickson 2005, p.*47).

http://mathworld.wolfram.com/AmicablePair.html

This 16 year old boy found something that escaped all the geniuses that came before him.
 
  • #64
agentredlum said:
5 out of 8 times you have problems i don't

The point is that we don't see minus signs as problems. A minus less or more means nothing to us...
 
  • #65
agentredlum said:
I NEVER have to compute a double negative for b

I NEVER have to compute a triple negative for +4ac

5 out of 8 times you have problems i don't

But this is my point, doing a double negative isn't, in any way, a problem for me. "Computing" a double negative is as simple as NOT writting a "-". It is easy.


agentredlum said:
Here is a fact about amicable numbers.

In 1636, Fermat found the pair (17296, 18416) and in 1638, Descartes found (9363584, 9437056), although these results were actually rediscoveries of numbers known to Arab mathematicians. By 1747, Euler had found 30 pairs, a number which he later extended to 60. In 1866, 16-year old B.*Nicolò I.*Paganini found the small amicable pair (1184, 1210) which had eluded his more illustrious predecessors (Paganini 1866-1867; Dickson 2005, p.*47).

http://mathworld.wolfram.com/AmicablePair.html

This 16 year old boy found something that escaped all the geniuses that came before him.


This is not what is going on, here.
 
  • #66
Robert1986 said:
Ahh, I see. But it only minimizes operations when you have a quadratic in one particular form, correct?

It minimizes operations in 5 out of 8 forms

62.5% of the time, i do less operations.

THAT IS A PHENOMENAL RESULT!
 
  • #67
micromass said:
The point is that we don't see minus signs as problems. A minus less or more means nothing to us...

What does it mean to a computer, in terms of memory allocation?
 
  • #68
agentredlum said:
What does it mean to a computer, in terms of memory allocation?

Aah, I was hoping that you would come to this! :biggrin:

The thing is that a computer keeps a bit that signifies the sign of a number. 0 if it's positive, 1 if it's negative. So whether a number is positive or negative: there is a bit allocated to the sign of the number! So your formula makes no difference at all in terms of computer memory.

And even if it did: I don't think a 30GB computer would have trouble with a little minus sign...
 
  • #69
agentredlum said:
What does it mean to a computer, in terms of memory allocation?

Haha. If you are doing standard arithmetic, it means nothing. The highest bit is the sign bit. 1 for negative and 0 for positive.
 
  • #70
This thread becomes trivial and useless. Locked.
 

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