How do you pronounce (partial) derivatives?

Question

I am not an English speaker that is why I asked this question. In addition, I think english.stackexchange.com is not the proper place to ask this because (I am so sorry) I don't think most of them know mathematics deeply.

How do you pronounce the following derivatives in English?

1. $\frac{\textrm{d}y}{\textrm{d}x}$
2. $\frac{\textrm{d}^2y}{\textrm{d}x^2}$
3. $\frac{\partial y}{\partial x}$
4. $\frac{\partial^2 y}{\partial x^2}$
5. $\frac{\partial^3 y}{\partial x^2\partial z}$

Feel free to edit the tag if it has been chosen incorrectly.

For example, is it correct if I pronounce $\frac{\textrm{d}y}{\textrm{d}x}$ as "dee wai over dee eks"?

Answer 1

This is how I personally pronounce them:

1. I pronounce it either "dee wai over dee eks" or simply "dee wai dee eks".
2. I occasionally pronounce it as "dee squared wai over dee eks squared", but more often I just refer to it as "the second derivative of y with respect to x".
3. "Partial of y with respect to x." Very occasionally as "del wai del eks".
4. As with 2, I usually just call this "the second partial of y with respect to x".
5. "del cubed y over del $x^2$ del z", but if we have $y=f(x,z)$, I'd much prefer referring to it as $f_{zxx}$.

Answer 2

3. $$ \frac{\partial y}{\partial x}\rightarrow\text{day wai, day eks}$$

5. $$ \frac{\partial^3 y}{\partial x^2\partial z}\rightarrow\text{day cubed wai, day eks squared, day zee}$$

6. $$\nabla F\rightarrow\text{del eff}$$

Answer 3

Personally I say

1. dee wai dee eks or dee wai over dee eks
2. dee eks over dee wai squared
3. partial wai partial eks or occasionally del wai over del eks (I think del in some areas is often the nabla symbol so not a lot of people use it)
4. partial wai over partial eks squared
5. partial wai cubed over partial eks squared partial zed

I do know a friend who pronounces 3 as doh y doh x or doh y over doh x so I think that is used sometimes too, I think any of these should work in most contexts