Is this sentence in good Esperanto?

La derivaĵo de du aŭ pli funkcioj de x, ke estas adiciantaj aŭ subtrahantaj, akireblas per adici aŭ subtrahi (basanta sur la patra funkcio) la derivaĵojn de ĉiu funkcio de x.

This is the intended meaning:

The derivative of two or more functions of x that are being added or subtracted is obtained by adding or subtracting (based on the parent function) the derivatives of each function of x.

Here is the correct translation, I think:

La derivaĵo de du aŭ pli funkcioj de x, kiuj estas aldonataj aŭ malaldonataj, estas akiritaj per la aldono aŭ malaldono (bazita sur la ĉefa funkcio) de la derivaĵoj de ĉiu funkcio de x.

Ello!

Can you say "pli funkcioj" or do you need to say "pli da funkcioj"? (I'm not sure)

Also doesn't "aldoni" mean "to add"? So in your correction (Hispanio), aren't you implying that the functions are doing the adding themselves? Whereas wouldn't "aldoniĝi" be "to be(come) added"?

Also, there is a lot of use of passive in the English, and long range dependencies (see how far "the derivative" is from "is obtained")? Might be clearer to put them closer and active?

And as Hispanio suggested, I think you do need a form of "kiu" instead of the "ke".

I'm unsure of how to say "parent" function too. "main" (ĉefa) may not do it, nor "patra" (parental?) So see mine below!

My stab:

Oni povas akiri la derivaĵon de du aŭ pli da funkcioj de x, kiuj kune aldoniĝas aŭ malaldoniĝas, per la aldono aŭ malaldono (bazita sur la patro-funkcio) de la derivaĵoj de ĉiu funkcio de x.

The mistake with ke/kiu seems to be quite common among native english speakers. I guess due to the fact, that the word that has several meanings in english; see the Wiktionary-page for more information.

I'm not sure, but I think the most easiest way to avoid this, is to check if you can replace it with this or which. If yes, you have to use a correlative, otherwise ke.

BlackOtaku:Is this sentence in good Esperanto?

La derivaĵo de du aŭ pli funkcioj de x, ke estas adiciantaj aŭ subtrahantaj, akireblas per adici aŭ subtrahi (basanta sur la patra funkcio) la derivaĵojn de ĉiu funkcio de x.

This is the intended meaning:

The derivative of two or more functions of x that are being added or subtracted is obtained by adding or subtracting (based on the parent function) the derivatives of each function of x.

I assume you're saying (for example) that if you have a function y = x^2 + sin(x) then y' = 2x + cos(x) ... i.e. similar to doing integration by parts.

I would have made my life easier by rephrasing it along the lines of :

Por kalkuli la derivaĵon de unu funkcio de x kiu konsistas el la sumo ǎu diferenco de du aŭ pli da funkcioj (de x), oni sumas ǎu subtrahas (depende de la originala funkcio) la derivaĵojn de la unuopaj funckioj de x.

Amike,

Paul

P.S. It might be relevant to mention that I'm an electrical engineer by profession

EldanarLambetur:Can you say "pli funkcioj" or do you need to say "pli da funkcioj"? (I'm not sure)

I'm pretty sure you would have to say "pli da funkcioj"

BlackOtaku:

The derivative of two or more functions of x that are being added or subtracted is obtained by adding or subtracting (based on the parent function) the derivatives of each function of x.

La derivaĵon de du aŭ pli multaj funkcioj de x sumigataj aŭ subtrahataj oni kalkulas per sumigado aŭ subtrahado (depende je la prafunkcio) de la derivaĵoj de ĉiu funkcio de x.

pdenisowski:

EldanarLambetur:Can you say "pli funkcioj" or do you need to say "pli da funkcioj"? (I'm not sure)

I'm pretty sure you would have to say "pli da funkcioj"

It absolutely has to be "pli da funkcioj"

Pli is grammatically a noun or an adverb, so you need a preposition to link it to a noun.

It's the same deal with "kiom", i.e. "kiom da funkcioj".

It's not just English speakesr who have a problem with kiu and ke; many Romance languages don't reliably distinguish between these words, so the speakers of those languages also make mistakes when choosing between ke and kiu.

erinja:

pdenisowski:

EldanarLambetur:Can you say "pli funkcioj" or do you need to say "pli da funkcioj"? (I'm not sure)

I'm pretty sure you would have to say "pli da funkcioj"

It absolutely has to be "pli da funkcioj"

Yes, I was just being polite If someone asked me if the Earth revolves around the sun, my answer would be "I'm pretty sure it does." (laughs)

It's not just English speakesr who have a problem with kiu and ke; many Romance languages don't reliably distinguish between these words, so the speakers of those languages also make mistakes when choosing between ke and kiu.

If you speak any languages where the relative pronoun has case, number, and gender (like German, Polish, Latin, etc.) you'd probably be much less likely to make this (common) mistake.

French speakers should be at least somewhat conscious of this given constructions like le(s)quel(s), although I recently saw a funny webpage pointing out how people often don't make this distinction in speech :

http://philippe.gambette.free.fr/danlekel/index....

Amike,

Paulk

Thanks for the help and clarifications everyone, I greatly appreciate it.