3. A snowball is rolling down the hill and its surface area is increasing at a rate of 3 cm2 /min. Find the rate at which the diameter is increasing when the diameter is 10 cm. (The surface area of a sphere is 472.) 4. Find the area under the curve y = (1 - cos x) sin x over the interval [0, 7] . 5. Find the volume of the solid generated by revolving the region bounded by 9 21 0 about them - axis . Explain which method you chose and why