CASE STUDY CHALLENGE

Application of Derivatives: Window Design

A window is in the form of a rectangle surmounted by an equilateral triangle on its length. Let the rectangular part have length and breadth x and y metres respectively.

Based on the given information, answer the following questions :

Answer the following:

(i) If the perimeter of the window is 12 m, find the relation between x and y. [1]
(ii) Using the expression obtained in (i), write an expression for the area of the window as a function of x only. [1]
(iii) (a) Find the dimensions of the rectangle that will allow maximum light through the window. (use expression obtained in (ii))

— OR —

(b) If it is given that the area of the window is 50 m2, find an expression for its perimeter in terms of x.

[2]