Name Algebra 1B activity and homework

September 29, 2008 “Lines on calculator”/”Perpendicular lines” page 1

Lines on calculator

Before starting, reset your calculator to the standard zoom (press ZOOM/ZStandard). It’s also a good idea to try 2nd MEM Reset Defaults.

Directions: Find function(s) that you can enter into your calculator to make a graph that approximately matches each of the screens shown below. Record the functions you use. Youwon’t have to use all of Y1 through Y6 in some of the problems.

1. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
2. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
3. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
4. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
5. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =


Directions: Find function(s) that you can enter into your calculator to make a graph that approximately matches each of the screens shown below. Record the functions you use. Youwon’t have to use all of Y1 through Y6 in some of the problems.

6. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
7. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
8. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
9. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =
10. / / Y1 =
Y2 =
Y3 =
Y4 =
Y5 =
Y6 =


11. Make a set of five lines that are all parallel to the line y = . Write their equations, graphall ofthem on your calculator, and draw a picture of your calculator screen.

equation one:
equation two:
equation three:
equation four:
equation five: / draw calculator screen:

12. Make a set of five lines all of which have y-intercepts at 2. Write their equations, graphallof them on your calculator, and draw a picture of your calculator screen.

equation one:
equation two:
equation three:
equation four:
equation five: / draw calculator screen:

Perpendicular lines

Vocabulary

What does it mean to say that two lines are perpendicular to each other?

Exploration

Directions: Each graph shows a pair of perpendicular lines. Find the slopes of the lines.

Generalization

When you have a pair of perpendicular lines, how are the slopes related?

The slope numbers are ______of each other.

Practice problems

13. Tell what the slope number would be for a line that is perpendicular to each of these lines.

a. line with a slope of

b. line with a slope of –

c. line with a slope of 5

d. line with a slope of –1

e. line with the equation y = x – 3

f. line with the equation y = –x + 1

g. line with the equation y = x + 7

h. line with the equation y = –4x – 2

i. line with the equation y = –x + 3

14. Draw three lines that are perpendicular to the line already shown on the graph.
Then write equations for all the lines on the graph.

equation for line already shown:
equation for first perpendicular line:
equation for second perpendicular line:
equation for third perpendicular line: /


15. Make a pair of perpendicular lines. One of the lines must have a slope of .
Write equations and draw graphs for both lines.

equation for line with slope of 4:
equation for the other line: /

16. Make a set of four lines that are all perpendicular to the line y = .
Write their equations and draw their graphs.

equation one:
equation two:
equation three:
equation four: /


17. The four lines in the graph form a rectangle.

a. Opposite sides of the rectangle are parallel to each other. What does this tell you about the slopes of opposite sides?

b. Sides of the rectangle that form a corner are perpendicular to each other. What does this tell you about the slopes of these adjacent sides?

c. Write equations for the four sides of the rectangle.

18. Add three more lines below to make a rectangle.
Then write equations for all four sides of the rectangle.

equation for line already shown:
equation two:
equation three:
equation four: /