Math 153 Lesson 12 Outline

Practice Quiz Solution (Practice problems for distance learning students)

1. Solve for x :

2. Solve for x :

Answering of homework questions over lesson 11.

Lesson 12 Section 2.3 (con’t)

Solving Quadratic Equations : ax² + bx + c = 0
(1) By factoring
(2) By completing the square
(3) Quadratic formula

Today: Applications

A baseball is thrown up with an initial velocity of 64 ft./sec. The number of feet , s, above the ground after t seconds is given by

(a) When will the ball reach a height of 48 feet?
(b) When will the ball hit the ground?

Example:

A rectangular swimming pool is 5 meters wide and 10 meters long. A tile border of
uniform width is to be built around the pool, using 100 square meters of tile. Find the width of the border.

A pizza box with a square base is to be made from a rectangular sheet of cardboard by cutting six 1-inch squares from the corners and the middle sections and folding up the sides (see figure). If the area of the base is to be 144 square inches, what size piece of cardboard should be used?

73)
The speed of the current in a stream is 5 mi./hr. It takes a canoeist 30 minutes longer to paddle 1.2 miles upstream than to paddle the same distance downstream. What is the canoeist’s rate in still water?

Quiz (Practice problems for distance learning students)

1. A ball is thrown upward with an initial velocity of 48 ft./sec. The number of feet , s, above the ground after t seconds is given by When will the ball hit the ground?

2. Set up the equation only —Do not solve or simplify:
A rectangular plot of ground having dimensions 26 feet by 30 feet is surrounded by a walk of uniform width. If the area of the walk is 240 sq. feet, what is the width of the walk?