# Homework Help: Clarification on Partial Derivative Symbols

1. Aug 26, 2010

### erok81

1. The problem statement, all variables and given/known data

2. Relevant equations

n/a

3. The attempt at a solution

I’ve never seen this format so I am not sure what it is asking. Taking L1.B as an example. They are partials, but does it mean partial of x with respect to z? And then partial of y with respect to z? I am pretty sure that part is right after looking at it again.

The one I am really confused about it L1.3D. There are two partial symbols with y and z in front of w. Maybe partial of x then y with respect to w?

And I guess the same thing with C. Partial of c1? Since c is a constant wouldn’t that be zero every time? There is no x with the partial symbols, so I don't think I do anything with the x or y?

I have only seen the following when referring to partial derivatives...

$$\frac{\partial x}{\partial y}$$
(partial of x with respect to y)

And...

$$F_{x}$$
(partial of x)

#### Attached Files:

• ###### L1.3.png
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2. Aug 26, 2010

### lanedance

$$\partial_x = \frac{\partial }{\partial x}$$

3. Aug 26, 2010

When in doubt, search Google/Wiki ;)! http://en.wikipedia.org/wiki/Partial_derivative

3B. partial of z with respect to x...and partial of z with respect to y.
3C. I'm not sure on this one. I guess partial of u w/ respect to c1, c2, c3, separately.
3D. partial of w with respect to y and then partial with respect to x.

4. Aug 27, 2010

### erok81

Perfect, that is what I was thinking. Thanks for the responses.

Back to the c1, c2, c3... since those are constants, isn't that just going to be zero? Or am I missing something still?

5. Aug 27, 2010

### Dick

Why do you think c1, c2 and c3 are constants? If you are taking partial derivatives of them, you shouldn't be thinking of them as constants.

6. Aug 27, 2010