# Question:simplify expression to complete derivative

## Question:simplify expression to complete derivative

Maple 2019

This

`expr:='1/r^2*diff(r^2*diff(v(r),r),r)'`

gives

And when evaluated second time it gives

`expr`

The question is, how to put expr back to its original form shown at the top?

I tried simplify, combine, etc.. but nothing puts back to same form.

The reason I am asking, is that I need put more complicated expression in form that resembles when I am looking at in textbook. For an example, the Laplacian

```VectorCalculus:-Laplacian(u(r,theta,phi),'spherical'[r,theta,phi])
```

But the above should be the same as

So I figured if I can rewrite each term to look like in the shorter version above (complete derivative version), it will be easier for me to compare what Maple gives and the text book shows,

ps. I found that the following command in Maples gives a little clearer Laplacian, but it is still not as simplified as the book but it is better than using VectorCalculus:-Laplacian

```Physics[Vectors]:-Laplacian(u(r,theta,phi));
```

At least this has each term a little more seprated.

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