Day 1 Problems 111108

1
Day 1 Problems 11/11/08

• Find the range.
• 12 15 17 28 30
• -12 -15 5 3 -2 0 -7
• Make a stem-and-leaf plot for each set of data.
• 18 35 28 15 36 10 25 22
  15
• 785 776 788 761 768 768 785

2
3.1 Inequalities and Their Graphs

• A solution of an inequality any number that
  makes the inequality true.
• For example solutions of the inequality x lt 3
  are all numbers that are less than three.

3
Identifying Solutions by Mental Math

• Is each number a solution of
• 9
• -1
• 9 is not less than or equal to 7.
• -1 is less than or equal to 7.

4
Identifying Solutions by Evaluating

• Is the number a solution of 2 5x gt 13?
• a. 3
• 2 5x gt 13
• 2 5(3) gt 13
• 2 15 gt 13
• -13 gt 13
• 3 does not make the original inequality true, so
  3 is not a solution.

5
Identifying Solutions by Evaluating

• Is the number a solution of 2 5x gt 13?
• b. -4
• 2 5x gt 13
• 2 5(-4) gt 13
• 2 20 gt 13
• 22 gt 13
• -4 does make the original inequality true, so -4
  is a solution.

6
Graphing and Writing Inequalities in One
Variable11/11/08

• You can use a graph to indicate all of the
  solutions of an inequality.
• Open dot less than or greater than
• Closed dot less than or equal to, greater than
  or equal to.
• Less than, less than or equal to line goes to
  the left
• Greater than, greater than or equal to line
  goes to the right.

7
Graphing Inequalities

• Graph c gt -2.
• Graph m 4.

-3
-2
1
2
3
0
5
-1
4
-3
-2
1
2
3
0
5
-1
4
8
Writing an Inequality from a Graph

• Write an inequality from each graph.
• a.
• x lt -4
• b.
• x 5

-7
-6
-3
-2
-1
-4
1
-5
0
-3
-2
1
2
3
0
5
-1
4
9
More Practice!!!

• Textbook p. 136 137 2 32 even.
• Homework Textbook - p. 136 137 1 31 odd.