Math Help - Derivative simplification.

1. Derivative simplification.

I'm not sure how to get from one expression to another.

According to maxima, the partial derivative of: $
\frac{x}{\sqrt{x^2+y^2+z^2}}
$
w.r.t x is:
Code:
(%i7) diff(x/(sqrt(x^2+y^2+z^2)),x);
2
1                   x
(%o7)                               ------------------ - -----------------
2    2    2      2    2    2 3/2
sqrt(z  + y  + x )   (z  + y  + x )
Which makes sense to me, but Maple somehow managed to simplify it to the following, which I don't know how they did:

Only the second term is what I'm interested in, as that is what differs.

Thanks.

2. Originally Posted by scorpion007
I'm not sure how to get from one expression to another.

According to maxima, the partial derivative of: $
\frac{x}{\sqrt{x^2+y^2+z^2}}
$
w.r.t x is:
Code:
(%i7) diff(x/(sqrt(x^2+y^2+z^2)),x);
2
1                   x
(%o7)                               ------------------ - -----------------
2    2    2      2    2    2 3/2
sqrt(z  + y  + x )   (z  + y  + x )
Which makes sense to me, but Maple somehow managed to simplify it to the following, which I don't know how they did:

Only the second term is what I'm interested in, as that is what differs.

Thanks.
Hi

The difference comes from the fact that your input for Maple is not correct since you forgot the square root

3. Ahh! Haha. Of course! Thanks for catching that