# Math Help - differentiation help please

Hi,

Can anyone give me the second derivative for the equation below:

$\frac{p^r}{(1-(1-p)e^t)^r}
$

I have done it but not sure if the answer is correct.

Thanks.

2. Show us what you did and we can say whether it is correct or not.

3. Originally Posted by Amazed
Hi,

Can anyone give me the second derivative for the equation below:

$\frac{p^r}{(1-(1-p)e^t)^r}
$

I have done it but not sure if the answer is correct.

Thanks.

i got something like this.. not sure whether it is correct or wrong

$\frac{r-rp^r(-e^t+pe^t)}{(1-(1-p)e^t)^{r+1}}
$

4. i got :

$\frac{r(p^r)(-r-1)((1-p)e^t)^2}{[1-(1-p)e^t]^(r+2)}
$

the r+2 is the power to which the denominator is raised to.. im just having trouble in typing it in the equation.

thanks

5. Mistyped in my last post.

And that's what i get for the second derivative:

$\frac{-r(p^r)(-r-1)((1-p)e^t)^2}{[1-(1-p)e^t]^{r+2}}

$