Day 3 (Jan. 27)
Look at the answer key for last time’s quiz in Blackboard.
Problem-solving Lesson 2.
Class discussion: Discuss inductive and deductive reasoning. Then do pages 23-25, exercises:
8, 10, 14, 22, 24, 26, 32
We also discussed how the material on writing linear formulas that was covered in the handout is
all deductive reasoning. We are using mathematical techniques that always work to do all the
steps to go from the original information to the formula for a line.
Homework is on pages 23-25:
1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 25 (and explain), 27 (and explain), 31, 33, 43, 45, 47, 51, 55, 57
Also, explain why the problem about temperature below (in the quiz) is using deductive
reasoning rather than inductive reasoning.
Quiz: (4 problems and two additional questions)
Problems:
1. Pages 23-25: 14,
2. Pages 23-25: 44
3. Pages 23-25: 50
4.
One can measure temperature in degrees Celsius or degrees Fahrenheit. The two measurements
are linearly related. The temperature at which water freezes is 0 degrees Celsius and 32 degrees
Fahrenheit. The temperature at which water boils is 100 degrees Celsius and 212 degrees
Fahrenheit.
Let y be the temperature Celsius and let x be the temperature Fahrenheit.
a. Write the two given facts as two points, in ordered pair notation, as (x,y) but with
numbers. Indicate which of these points you will call ( x1 , y1 ) and which you will call
( x2 , y2 ) .
b. Use these points to find the slope and y-intercept and write the formula for the
line to express the relationship.
c. Interpret the slope. (The variable y is measured in degrees Celsius and the variable x is
measured in degrees Fahrenheit.)
d. Interpret the y-intercept. (Be sure to mention the units of each variable.)
5. Question: Are you able to find the course webpage and see the assignment for the day on it?
6. Question: Are you able to get into Blackboard and see the answer key for the quiz over linear
formulas that was assigned on Day 1. (Not all answer keys will be posted. About half of them
will. You are expected to come to class, pay attention, and take notes on what you will need
later. )