Oct. 15 Class

Today we began solving world problems involving quadratic functions.

Here is a handout: Zero word problems

All of these problems involve finding the zeroes of quadratic functions.  You must be able to

• Interpret the problem.
• Write a mathematical statement.  (Let statement if necessary.)
• Solve the problem by finding the zeroes.
• Interpret the solutions by writing a concluding statement.

Here are the solutions to the first few questions on the handout:

Page 55

1. (a) The ball was in the air for 4.1 seconds.

1. (b) The ball was above 17 m for 2 seconds.

2.  The tile is 3cm by 8 cm.

3.  The matte must be 10 cm wide.

Page 57 

1.  The numbers are 14 and 16 or they can also be -16 and -14.

2.  The two sides are 9 cm and 12 cm.

3.  The width of the strips must be 20 m.  (-120 is not physical.)

4.  The speed is 600 km/h.  (-700/13 is not physical.)

The solutions to the rest of the handout are printed at the bottom of the page.

Homework: 

g. 178 #6ac, 7-14

P. 185 #11, 13-16