1. An open box is to be made from a square piece of cardboard with the dimensions 30 inches by 30 inches by cutting out squares of area x² from each corner, as shown in the figure.

(a) Express the volume V of the box as a function of x. V =

(b) State the domain of V. (Enter your answer using interval notation.)

2. f(x) sqrt{20-x²}

3. Find the distance between the points whose coordinates are given. sqrt{2}, sqrt{12}, sqrt{18}, sqrt{32}