# Math Help - Expanding formula

1. ## Expanding formula

Im trying to understand some notes, can someone please explain if the following is the case?

$d/dr [r * da/dr ]$

does this equal

$da/dr + r * d^2a / dr^2$

Thanks

Calypso

2. Originally Posted by calypso
Im trying to understand some notes, can someone please explain if the following is the case?

$d/dr [r * da/dr ]$

does this equal

$da/dr + r * d^2a / dr^2$

Thanks

Calypso
Your calculation is correct.

3. Has these being done using the product rule?

4. Originally Posted by calypso
Has these being done using the product rule?
Yes.