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I saw this question and with my basic knowledge of differentiation I don't know what it means. $\frac{d}{dx}(x^2)$ where $x=3$

Where would I start to solve this?

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    @psp: Good catch! Yes.2011-11-14

1 Answers 1

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The derivative of a function is related to the concept of the rate of change of a function.

Either you use the method presented by @Arturo Magidin, or you apply a formula.

An example of a formula is for:

$f(x) = x^{n} $

the derivative (denoted by either {f}'(x) or $\frac{d}{dx} f(x)$ is

$ n x^{n-1} $

so in you case (n=2)

$f(x) = x^{2} $ and $\frac{d}{dx}f(x)= 2 x^{2-1} = 2x$

at point x=3

{f}'(3) = 2*3 = 6