Need help on this calculus work!!!?

As the breeding season progresses, penguins parents have to devote a bigger proportion of their catch to feed their chicks, until they fledge and are able to feed by themselves. The following equation describes this phenomenon, where P us the proportion of prey given to chicks and t is time in weeks over the course of the breeding season: P(t)=t^2/(230+t^2). Determine the function that describes the rate of change in the feeding behavior of the penguin parents. What can we learn about the biology of penguins through the analysis of this function?