Even and odd at the origin
a. If ƒ(0) is defined and ƒ is an even function, is it necessarily true that ƒ(0) = 0? Explain.
Draining a tank (Torricelli’s law) A cylindrical tank with a cross-sectional area of 10 m2 is filled to a depth of 25 m with water. At t=0 s, a drain in the bottom of the tank with an area of 1 m² is opened, allowing water to flow out of the tank. The depth of water in the tank (in meters) at time t≥0 is d(t)=(5−0.22t)2.
b. At what time is the tank empty?