1. More applications of a quadratic function

2. Example The length and width of a rectangle are (3x + 1) and (2x – 1) cm respectively. If the area of the rectangle is 144 cm 2, find x. Identify the unknown! Form the equation! Solve! Are both answers acceptable? (rej)

3. Example A rectangular swimming pool measures 25 m by 6 m. It is surrounded by a path of uniform width. If the area of the path is 102 m 2, find the width of the path. Let the width be x. Therefore, length of path = 25 + 2x, breadth of path = 6 + 2x 25 m 6 m 25 + 2x 6 + 2x Area of pool = 25 x 6 = 150 m 2 Ans: The width of the path is 1.5 m

4. Example – Remember Abigail? ZAbigail, who has a bionic arm, is crossing a bridge over a small gorge and decides to toss a coin into the stream below for luck. The distance of the coin above the water can be modeled by the function y= -16x 2 +96x+112, where x measures time in seconds and y measures the height, in feet, above the water. ZFind the time at which the coin hits the water.

5. Example ZJack and Jill have a lemonade stand in a really good location and want to increase their prices. They figure out the equation that models their business profit is P(x)=-2x 2 +11x-12. ZWhat would you do to find their maximum profit??? ZAt what price per cup would their profit be zero?