Review: 6.5h Mini-Quiz

1. Solve: An object is dropped from a cliff 480 ft above the ground. Find the time t (in sec) for the object to reach the ground by solving the equation: –16t2 + 1600 = 0

2. Solve: A diver jumps from a diving board that is 80 ft above the water with an initial velocity of 64 ft per sec. The height h (in ft) is modeled by the position equation: h = –16t2 + 64t + 80 where t is the time measured in sec. How long will it take for the diver to reach the water?

Objective: Students will solve real world word problems involving quadratic equations. (continued)

Solving real world word problems involving Quadratic Equations

(continued)Chapter 6 – Factoring and Solving Equations

Section 5i

Let w = the width of the picture frame

A = l w

w(w + 4) = 32

w2 + 4w -32 = 0

Solve: The length of a rectangular picture frame is 4 inches greater than its width. The area of the picture frame is 32 square inches. Find the dimensions of the picture frame.

Then w + 4 = the length of the picture frame

(w + 8)(w – 4) = 0w = {-8, 4}Answer: the width is 4 and the length is 8

MUST BE POSITIVE

Preview 370/63The length of a rectangular poster is 2 times its width. The area of the poster is 648 square inches. Find the dimensions of the picture frame.A = l wLet w = the width of the picture frame

Then ? = the length of the picture frame

Preview 370/65An open box is to be made from a square piece of material by cutting two-inch squares from the corners and turning up the sides (see figure).

a) Show that the volume of the is box is given by V = 2x2

b) Complete the table.

c) Find the dimensions of the original piece of material when V = 200 cubic inches.

Homework

370/61-65 odd

Lesson Summary: Objective: Students will solve real world word problems involving quadratic equations. (continued)

Preview of the next Lesson: Objective: Students will solve real world word problems involving quadratic equations. (continued)