My teacher gave my class, which is sick, and I need help with a couple questions.
1. A rectangular box with a volume of ft^3 is to be constructed with a square base and top. The cost per square foot for the bottom is 15 cents, for the top is 10 cents, and for the sides is 2.5 cents. What dimensions will minimize costs
2. A cone shaped icicle is dripping from the roof. The radius of the icicle is decreasing at a rate of 0.3cm/hr. While the length is increasing at a rate of 0.9 cm/hr. If the icicle is currently 9cm in radius and 18 cm long, is the volume of the icicle increasing or decreasing, and at what rate?