ƒ(x) = 1/x+2

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- Jun 17th 2013, 02:11 AMbrosnan123Derivative
ƒ(x) = 1/x+2

- Jun 17th 2013, 02:16 AMProve ItRe: Derivative
1. Why have you put a question about a Derivative in Pre-Calculus when it is clearly Calculus?

2. Some brackets where they're needed to avoid ambiguity would be nice. Is your function $\displaystyle \displaystyle \begin{align*} f(x) = \frac{1}{x} + 2 \end{align*}$ or $\displaystyle \displaystyle \begin{align*} f(x) = \frac{1}{x + 2} \end{align*}$?

3. Have you tried anything? Please post what you have tried and exactly where you are stuck. - Jun 18th 2013, 02:46 AMmpx86Re: Derivative
use $\displaystyle \[\mathop {\lim }\limits_{h \to 0} (f(x + h) - f(x))/h\]$ and find the answer

by the way we write f(x+h) by replacing x by x+h everywhere in the function.... - Jun 18th 2013, 05:23 AMHallsofIvyRe: Derivative
brosnan123, because you have shown no attempt yourself, we have no idea what methods you can, or are allowed, to use. mpx86 indicated a method using the basic definition. But there are also many "rules", such as the "power rule" (the derivative of x^n is nx^(n-1)) that could be applied here.