h 2x A crate used on fruit farms in the Ping River valley is in the form of a rectangular prism which is open on top. It has a volume of 1 cubic metre. The length and the breadth of its base is 2x. and x metres respectively. The height is h metres. The material used to manufacture the base of this container costs R200 per square metre and for the sides, R120 per square metre. 9.1 Express h in terms of x 9.2 Show that the cost, C, of the material is given by: C(x)=400x²+360x 9.3 Calculate the value of x for which the cost of the material will be a minimum. 9.4 Hence, calculate the minimum cost of the material. (2) (3) (2) (2) བྱེ ་གྱི སྤྱི སྤྱི​