# Need help figuring out $\frac{d}{dx}(x^2)|{x=3}$

Okay, I punched this into my new calculator:

$$\frac{d}{dx}(x^2)|{x=3}$$

and it all is equal to $6$. What is this called and/or what does it do?

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Evaluating a derivative of x^2 in respect to x at a fixed point (x = 3). Where did the sin term come from (another question)? – Amzoti Sep 28 '12 at 1:51
I got rid of it. I was just trying to figure out the math coding thing – Gᴇᴏᴍᴇᴛᴇʀ Sep 28 '12 at 1:52
Ok its called a derivative. Thank you Amzoti. – Gᴇᴏᴍᴇᴛᴇʀ Sep 28 '12 at 1:53
You shouldn't write a "thank you" as an answer. This site does not function as a forum where you can write posts. It is a question and answer format. Please see the FAQ. – Thomas Sep 28 '12 at 2:01
Yeah and under etiquette it says to be nice. not vote people down for saying "thank you" – Gᴇᴏᴍᴇᴛᴇʀ Sep 28 '12 at 2:14

## 1 Answer

Use simple derivative formula to solve this problem.

In this case use the formula:

$\frac{d}{dx}(x^2) = 2x$

Now put $x=3$

Answer will then come to $6$

For formulas, you may refer to: Basic Differentiation Formulas

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