Solving for Area: An Oil Slick of Radius 3.0 km

[Nitrate]

Homework Statement

1. An oil tanker springs a leak creating a circular oil slick that grows until its radius is 3.0 km.

a.) What is the formula describing the relation between the area of the slick and its radius?

Homework Equations

Area of a circle: (pi)r^2

The Attempt at a Solution

Is the equation for a) y = (pi)r^2,
or is it the derivative: y = 2(pi)r?

 

[vrmuth]

a.) What is the formula describing the relation between the area of the slick and its radius?

I think you mean the difference between the RATE OF CHANGE of the area of the slick and that of the radius , please make it clear .

 

[HallsofIvy]

The formula you give $A= \pi r^2$ relates the area of a circle to its radius. There is nothing said in your problem, at least the part you posted, about rates of change.