bendy light?

differential calculus, which comes in elementary

a + c = c and that there needs to be a balance on both sides of the = operator. That's the pre-kindergarten stuff I'm talking about.

For those of you who slept through calculus at high school (Parsifal, I'm looking at you!), here's an example of derivatives:

Parsifal, assuming you know the message dog is trying to convey, tell me the correct way to say it (not that his way is incorrect). Should it be "I have calculated the first derivative of the expression 3/4 cuberoot(Bx^4/c^2) with respect to x regarding B as the Bishop constant and C as the rate of change of position of a photon travelling in a vacuum in a straight line over a given interval of time (T)." If you can't tell what he's saying, you're stupid. If you are trolling, you're stupid. Either way, you're stupid.

Why do you waste everybody's time with shit like this and then complain about markjo in S&C for one comment.

you are stuck in equations from pre-kindergarten school. Go read this stuff: What is a derivative?

I could be wrong, but I think Parsifal was trying to point out that derivatives are only found for functions, not equations.  Not all equations are functions.

getting a derivative is an operation.

However its a pretty weak objection since "taking the derivative of an equation" is pretty commonly used.

Even if what you were saying is true, the equation in question is a function.

In the equation being discussed, I think everybody is assuming y=f(x).

Good to know I'm not the only one who thinks Parsifal is an imbecile haha

Quote from: PizzaPlanet on March 19, 2013, 06:43:13 AM

Quote from: mosFET on March 19, 2013, 12:01:08 AM

you are stuck in equations from pre-kindergarten school. Go read this stuff: What is a derivative?

Shit, you did differential calculus when you were 3-5 years old? Now I feel bad about myself.

No, you wimp. He only knows equations from pre-kindergarten. That's why he can't understand basic differential calculus, which comes in elementary. Sometime after that comes advanced differential calculus at university level. This guy only knows a + c = c and that there needs to be a balance on both sides of the = operator. That's the pre-kindergarten stuff I'm talking about.

Now I'm perplexed. Y cannot be conceived as the function of x?

How the hell then is the formula applied to the real world? As long as we are not told how the formula is supposed to work we can only guess.

And why do you only tell people that their guesses are wrong without really explaining your point? I can't speak for other people, but I am sick of your one liners. What is this? Is it science or is it only a game?

No function f has yet been defined in this discussion. Assuming its existence is illogical.

If you wish to take the derivative of a function f, then please define a function f before doing so.

What makes you think I don't know what a derivative is?

An equation does not have a "first derivative". Be more specific.

Quote from: Homesick Martian on March 22, 2013, 06:46:56 AM

How the hell then is the formula applied to the real world? As long as we are not told how the formula is supposed to work we can only guess.

The equation is explained in detail on the wiki page linked in the first reply in this thread

Argumentum ad populum deals with beliefs, not informalities in speech. If you can't deal with informalities on an internet forum, then you should find another way to spend your time.

You don't understand function notation?

Tell me then, what is the relation, if there is any, between Y and X in the equation?

Quote from: Parsifal on March 22, 2013, 03:26:16 AM

What makes you think I don't know what a derivative is?

Quote from: Parsifal on March 17, 2013, 11:29:42 AM

An equation does not have a "first derivative". Be more specific.

Argumentum ad populum is a logical fallacy, regardless of the attempted point being made. Either you are asserting that because it is commonly used, it is a valid way of communicating, in which case you are committing argumentum ad populum; or you are stating that it is commonly used and not concluding that it is a valid way of communicating, in which case it is irrelevant.

What makes you think that?

Precisely what the equation declares it to be.

With your logic, language should never have been invented. In a time when communication involved grunts and/or physical expressions, this would be equivalent to thinking that using one particular sound to mean a certain idea is argumentum ad populum.

This is silly. We're not talking about a fundamental truth here. We are talking about a concept that is manmade with a notation that is manmade that is given room to evolve. With your logic, language should never have been invented. In a time when communication involved grunts and/or physical expressions, this would be equivalent to thinking that using one particular sound to mean a certain idea is argumentum ad populum. It is not appealing to the pressure of the masses, it is a more effective, efficient means of communication. With your logic, even your well thought out, succinct responses are argumentum ad populum. Our language has Latin roots. At some point, those Latin sounds that represent ideas changed massively to form modern english. Although it takes time for new words/phrases to catch on and become acceptible language, nobody will dispute that the phrase in question is acceptable language and effective, efficient means of communication. If that conclusion is true, then your assertion is irrelevant and without consequence.

Quote from: Parsifal on March 22, 2013, 06:38:47 PM

What makes you think that?

y=f(x) is the notation used to express the idea that a variable y is a function with respect to x. y is a dependent variable. x is independent.

Based on the previously given explanation of function notation, as well as information regarding the variables in the wiki, it appears that the value of y is dependent upon the value of x, in which case y can be formally expressed as a function of x, by the equation y=f(x).

Quote from: burdenofproof on March 22, 2013, 07:41:01 PM

With your logic, language should never have been invented. In a time when communication involved grunts and/or physical expressions, this would be equivalent to thinking that using one particular sound to mean a certain idea is argumentum ad populum.

What?

Quote from: PizzaPlanet on March 22, 2013, 08:16:09 PM

Quote from: burdenofproof on March 22, 2013, 07:41:01 PM

With your logic, language should never have been invented. In a time when communication involved grunts and/or physical expressions, this would be equivalent to thinking that using one particular sound to mean a certain idea is argumentum ad populum.

What?

finish reading the post. It may clarify some things.

This would be valid reasoning if any sense could be made of the phrase "the derivative of an equation". However, since an equation does not have a derivative, it is not. If everyone in the world responded to the question "what colour is the sky?" with "rhubarb", that would not make it a valid answer to the question because rhubarb is not a colour.

Irrelevant.

It is not valid to use a function before declaring it.

It is possible to define a function f such that y = f(x). It is also possible to define a function f such that y = f(c). In each case, f would be a different function with a different derivative function.

In the equation being discussed, I think everybody is assuming y=f(x).

Quote from: burdenofproof on March 22, 2013, 08:34:05 PM

Quote from: PizzaPlanet on March 22, 2013, 08:16:09 PM

Quote from: burdenofproof on March 22, 2013, 07:41:01 PM

With your logic, language should never have been invented. In a time when communication involved grunts and/or physical expressions, this would be equivalent to thinking that using one particular sound to mean a certain idea is argumentum ad populum.

What?

finish reading the post. It may clarify some things.

I did, but sadly it immediately veered off into completely irrelevant (and completely wrong, but that's beside the point) stuff about how languages developed when they had already existed.

I do not claim to understand the precise evolution of language

Parsifal conceded that my reasoning was correct

Quote from: burdenofproof on March 22, 2013, 09:04:30 PM

I do not claim to understand the precise evolution of language

That's reassuring.

Quote from: burdenofproof on March 22, 2013, 09:04:30 PM

Parsifal conceded that my reasoning was correct

Argumentum ad Parsifalum.

straw man. As explained, the phrase in question is widely used and widely understood, and by your own admission, my reasoning is valid if those conditions are met. I can site multiple sources where the same phrase is used and understood by all present in the discussion. Would you like me to?

It's relevance hinges on your concession that y is a function of x.

By the defintions presented in previous posts, we know that if y is dependent on x (it is in the equation), y can be expressed as a function of x. Again, this can be written y=f(x). I refer to my post that stemmed the debate.

Quote from: burdenofproof on March 19, 2013, 01:19:02 PM

In the equation being discussed, I think everybody is assuming y=f(x).

This is me defining y as a function of x. You said I was naive to assume this.

I request that, before anything else, you address this question. In the equation, is y a function of x?

This would be valid reasoning if any sense could be made of the phrase "the derivative of an equation".

Irrelevant.

Irrelevant.

Irrelevant.

If it is so widely understood, then please tell me what the "derivative of the equation" is for this equation:

2 + 2 = 4

It is irrelevant to my question, which asked what makes you think I do not understand function notation.

Can be, yes. Was (prior to the post you refer to), no.

No, I said that it was illogical to assume that y = f(x) before f has been defined.

Yes.

Quote from: Parsifal on March 23, 2013, 01:29:43 AM

If it is so widely understood, then please tell me what the "derivative of the equation" is for this equation:

2 + 2 = 4

This equation is not a function. I thought you took calculus.

I defined function notation and explained it's relevance within the argument. You accepted the definition, yet you reply with a fragment of a thought. How is the definition of function notation irrelevant in understanding function notation? Even if it doesn't directly address your question, how is the information irrelevant?

Quote from: Parsifal on March 23, 2013, 01:29:43 AM

Can be, yes. Was (prior to the post you refer to), no.

Did you forget subject nouns? That post didn't make much sense.

Quote from: Parsifal on March 23, 2013, 01:29:43 AM

No, I said that it was illogical to assume that y = f(x) before f has been defined.

It is a function by the nature of the equation, and other information on the wiki verifies this.

Why is the act of defining y as a function of x necessary when it is inherent in the nature of the equation?

No equation is a function. That aside, we are discussing the phrase "derivative of the equation", not functions.

It is irrelevant to my question, which asked what makes you think I do not understand function notation.

My intended meaning was that, prior to the post in which you first used f(x), nobody had declared or defined such a function. While it is perfectly valid to assume such a function's existence after it has been declared, it is illogical to do so before it has been declared.

Irrelevant.

It is not.

Quote from: Parsifal on March 24, 2013, 04:20:17 AM

It is not.

I'm glad we both agree that it is not necessary [...]

Quote from: burdenofproof on March 24, 2013, 09:01:55 AM

Quote from: Parsifal on March 24, 2013, 04:20:17 AM

It is not.

I'm glad we both agree that it is not necessary [...]

hehehe i get it
he didn't specify what he means so you took the inverse of it
lol gud 1

Quote from: PizzaPlanet on March 24, 2013, 09:15:11 AM

Quote from: burdenofproof on March 24, 2013, 09:01:55 AM

Quote from: Parsifal on March 24, 2013, 04:20:17 AM

It is not.

I'm glad we both agree that it is not necessary [...]

hehehe i get it
he didn't specify what he means so you took the inverse of it
lol gud 1

How can I take the "inverse" of what he posted? That doesn't even make sense. ur retarted.

something of a contrary nature or quality

I had poor word choice. The equation does not contain a function. If an equation contains a function, the phrase in question is valid.

• f(x) = x² - 3
  
• g(y) = 1 / y
  

Although I did not directly address the question, the information presented provides a background with which we can establish mutual agreement upon fundamental concepts before your query is discussed. Your posting of 'irellevant' leads me to beleive you do not understand the connection between the phrase "function notation" and the equation y=f(x). Do you see any relation between these two things or are they two completely unrelated, distinct concepts, as your posts imply.

The wiki declares the function, as I have stated more than once.

"Where (0,0) is understood to be the point at which the light ray is horizontal (that is, the derivative of this function is zero)."

Again, a function has already been defined. it is relevant.

I'm glad we both agree that it is not necessary, but you seem to be contradicting yourself. Have you forgotten what side you're arguing?

Here is an equation which contains a function:

q = f(x) + 2 * g(y) - 7p

Where the functions f and g are defined as:

• f(x) = x² - 3
  
• g(y) = 1 / y
  

Please tell me what the derivative of this equation is.

They are related.

The wiki merely (and ambiguously; this was my error dating from four years ago) refers to y as being a function of x. It does not declare a function f, which is the point being contended.

No.

I have made no such contradiction.