Differentiation - cant remember

1. Jul 14, 2010

pat666

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

for the question and attempt see the attachment. ive nearly done this but from my ti-89 I know that i am missing a 2x from the top line and i cant find where its gone. been a while since ive done this and i think that its just a simple mistake... ps it does want the double differential but once i get the first diff right i should be able to finish it off...... thanks for any help.

2. Relevant equations

3. The attempt at a solution

Attached Files:

• diff.png
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2. Jul 14, 2010

Staff: Mentor

The 2x is missing because you forgot that you need to use the chain rule.

3. Jul 14, 2010

pat666

so i did- thanks for that.