An oil spill on the open sea in calm weather spreads in a circular pattern. If the radius of the oil spill increases at the rate of 0.9m/s, how fast is the area of the spill increasing when its radius is 225?

You do know the formula for the area of a circle, right? You're looking to take its derivative with respect to time - try it and post back with what you get.

@ EBAINES.Please verify my method below.A=πr²dr/dt = 0.9m/sr = 225mdA/dt = 2πr(dr/dt)dA/dt = 2π(225)(0.9)dA/dt = 1272m²/sThanks in advance

@ EBAINES


A=πr²
dr/dt = 0.9m/s
r = 225m


dA/dt = 2πr(dr/dt)
dA/dt = 2π(225)(0.9)
dA/dt = 1272m²/s


Thanks in advance

Quote:

---

Originally Posted by MartinBrits

dA/dt = 1272m²/s

---

Correct!