At a certain instant each edge of a cube is 5 inches long

Question

1. At a certain instant each edge of a cube is 5 inches long and its surface area is increasing at a rate of 2in²/min . How fast is the volume of the cube increasing?

2. Use linear approxiamation L(x) to an appropriate function f(x), with an appropriate value of a, to estimate the number √28.

3. Find the following limit, lim_x→0+ (e^2x - 1)^x.