2 the chart below contains a portion of the fuel

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: selling x hundred LCD TVs is given by R(x) = −5x3 + 35x2 + 155x for x ≥ 0, while the cost, in thousands of dollars, to produce x hundred LCD TVs is given by C (x) = 200x + 25 for x ≥ 0. How many TVs, to the nearest TV, should be produced to make a profit? Solution. Recall that profit = revenue − cost. If we let P denote the profit, in thousands of dollars, which results from producing and selling x hundred TVs then P (x) = R(x) − C (x) = −5x3 + 35x2 + 155x − (200x + 25) = −5x3 + 35x2 − 45x − 25, where x ≥ 0. If we want to make a profit, then we need to solve P (x) > 0; in other words, −5x3 + 35x2 − 45x − 25 > 0. We have yet to discuss how to go about finding the zeros of P , let alone making a sign diagram for such an animal,4 as such we resort to the graphing calculator. After finding a suitable window, we get We are looking for the x values for which P (x) > 0, that is, where the graph of P is above the x-axis. We make use of the ‘Zero’ command and find two x-intercepts. 4 The procedure, as we shall see in Chapter 3 is ident...
View Full Document

This note was uploaded on 05/03/2013 for the course MATH Algebra taught by Professor Wong during the Fall '13 term at Chicago Academy High School.

Ask a homework question - tutors are online