# Implicit Differentiation on TI-Nspire CAS

• April 8th 2009, 08:12 AM
laughfactory
Implicit Differentiation on TI-Nspire CAS
Hi there, I'm trying to do the following implicit differentiation on my TI-Nspire CAS, and I can't figure it out.

$v = \frac{1}{3} \pi r^2 h$

I want to get: $\frac{dv}{dt} = \frac{2}{3} \pi r \frac{dr}{dt} \frac{dh}{dt}$

Is there any way to get the Nspire to produce that sort of output?

I know that ImpDif of $x^2 + y^2 = 36$ can be implicitly derived by the Nspire to yield $\frac{-x}{y}$ but how about cases where a function is being derived with respect to a variable not found in the function itself (like $t$ as in the case above)? (if this makes sense)

Warm regards,

Abe