First and second derivative assistance please?

[Khamul]

Homework Statement

r = 2/(2 - cos (\pi*t))

Homework Equations

N/A

The Attempt at a Solution

Hello everyone, first I would just like to say (which is obvious since I'm asking ) That it's been a long long time since I've had to do derivatives, hence my total cluelessness with this. I've had to integrate frequently in my engineering courses, but this is a problem that arose in my dynamics class...and embarrassingly enough, I'm not even sure where to begin.

Could someone help me out? I'm going to be unable to proceed with my problem (it involves radius of curvatures) until I get the first and second derivatives of this bad boy. Thanks in advance!

 

[berkeman]

Homework Statement

r = 2/(2 - cos (\pi*t))

Homework Equations

N/A

The Attempt at a Solution

Hello everyone, first I would just like to say (which is obvious since I'm asking ) That it's been a long long time since I've had to do derivatives, hence my total cluelessness with this. I've had to integrate frequently in my engineering courses, but this is a problem that arose in my dynamics class...and embarrassingly enough, I'm not even sure where to begin.

Could someone help me out? I'm going to be unable to proceed with my problem (it involves radius of curvatures) until I get the first and second derivatives of this bad boy. Thanks in advance!

Here's the wikipedia page that will help you out:

http://en.wikipedia.org/wiki/Quotient_rule

I just remember it as "The bottom multiplied by the derivative of the top, minus the top multiplied by the derivative of the bottom, all over the bottom squared."

 

[Khamul]

Aha! THAT'S the bugger I forgot. I kept thinking of the product rule, and how utterly insane it made this. This helps a bunch, thank you :)