Integraluser

Yeah, this is a literal translation:

If that rate of change of function f when x changes from x to x+h equals $\displaystyle 6x^2h - 3xh^2$, whereas h is a real number approaching 0, find f'(-2)


it has no answer choices, it needs the solution written with steps and so.

skipjack

Was the textbook written by a committee rather than a professional mathematician?

Integraluser

Yeah a committee I assume, 4 doctors administrated its authorship and 6 have written it, 3 among of whom are doctors according to the book. It's even the official book by the ministry of education being taught in schools, not sure why this mistake is there twice.

Doesn't matter actually, it's fine since I've got your opinions regarding it and we agreed on the same point (that it should be "change in y" rather than "rate of change"). I might of tell someone who can do something about it so that it gets fixed.

skipjack

Even if "rate of" is omitted, the questions are flawed.

Integraluser

Why so?

skipjack

Try to find a function with the specified property.

Integraluser

Oh alright, maybe the nearest function would be $\displaystyle x^3$ but you are right. I think they made it like this just to make it suit their wanted idea.