Question

# The area of a circular sunspot is growing at a rate of 500 style="color:rgb(0,0,0);"> km^{2}/sec.

(a) How fast is the radius growing at the instant when it equals 3,000 kilometers? HINT [See Example 1.] (Round your answer to three decimal places.)

(b) How fast is the radius growing at the instant when the sunspot has an area of 250,000 square kilometers? HINT [Use the area formula to determine the radius at that instant.] (Round your answer to four decimal places.)

^{2}/sec.