In exercises 6 - 7, find a formula for the described function and state its domain. 6. The area of a rectangle is 100 m2. Express the perimeter as a function of the length of one of its sides. 7. A right circular cone is inside a cube. The base of the cone is inscribed in one face of the cube and its vertex is in the opposite face. Express the volume of the region between the cone and the cube as a function of the length of the edge of the cube. In exercises 8, the rule of a function f is given. Write an algebraic formula for f(x) where x is the input. 8. Take the cube of the input, multiply by 3, add 5, and divide the result by the input. 9. At noon, a car leaves town A on a street road, heading south at 60 km/h, and a plane 4 km above the ground passes over town A heading east at 650 km/h. (a) Express the distance r travelled by the car and the distance s travelled by the plane as functions of time. (b) Express the distance d between the plane and the car in terms of r and s. (c) Express d as a function of time. (d) How far apart were the plane and the car at 1:30PM? 10. The rule of the function fis given by the graph below.