Transcript August 25, 2011 Welcome to Ms. Wu`s math class!

January 9
Ms. Wu says … follow the instructions below!
1) Find your new seat.
2) Get out HW 3.2 (don’t have to tear out).
3) Get started on the warm up quietly.
4) Grade HW 3.2.
_______________________________________________
4. (-3, 29)
27.(-4, 12)
7. (5, 7)
32.(10, 6)
10. (-2, 2)
34. a. 2 = m + b; 12 = -4m + b
13. (4, 5)
b. m = -2, b = 4
16. (-15, -62)
c. y = -2x + 4
20. (5, 3)
35. L = 4.5 ft; w = 2.5 ft.
23. The two equations should be subtracted rather than
added; 6x – 8; x = 4/3
New stuff for 2nd semester:
• Warm ups
– Will not be turned in; grade in class; 10% final grade; points
deducted for talking/not doing it/being off-task
• Quicky quizzes
– Every class period; worth 5 – 10 pts; drop 2 lowest scores; if
absent, counts as dropped score
• Late homework
– Name on door for a week; if not crossed off, mandatory tutorials
(call home)
• Homework quizzes
– Worth 10 pts.; can use homework; cannot drop or make up; if
absent, grade homework as quiz
The Elimination Method, pt. 2
Ex1: 3x – 4y = 14
2x + 2y = 21
The Elimination Method, pt. 2
Ex 2: 5x – 6y = 12
3x – 5y = 24
The Elimination Method
Process:
1) Pick the variable you want to eliminate.
2) Multiply one, or both, equations by a value to
make sure the coefficients of the chosen variable
are the same (for subtraction) or opposite (for
addition).
3) Subtract/Add and Solve the resulting equation.
4) Go back to one of the original equations and
solve for the other variable.
Group Activity
• Study the following Linear Inequalities and
determine at least 5 different points (x, y) that
make each inequality true.
A) x ≤ 4
B) y > -2
C) y < ½ x – 2
D) 2x – y ≥ 4
• Plot the points on the board. You cannot plot
the same point as another group!
• What do you notice about the points that make
each linear inequality true?
A
Graphs from the activity.
B
C
D
Steps to Graphing
1) Graph the boundary line
2) Determine if the boundary is inclusive (solid
line) or exclusive (dotted/dashed line)
3) Test a point and shade the appropriate half
plane.
Graphing Linear Inequalities
The graphs consist of
1) Boundary Line (graph of corresponding equation)
---- for exclusive
___ for inclusive
2) Half-Plane (shaded to indicate included points)
Half-Plane: The points on a plane that fall on one side of
a boundary line.
Sample Problems
1) Determine if (4, 5) is a point that satisfies
4x + 2y < 12
2) Write inequalities that describes the
graphs below.
SIGMA #3
• 10 pt class work grade
• 30 minutes, calculators allowed
SIGMA Score
Classwork Grade
8
13
7
12
6
11
5
10
4
9
3
8
2
7
1
6
0
5
Quicky Quiz
• 5 minutes
• Worth 5 points
• No notes allowed
HW 3.3
• Pgs 454 – 455: 5, 7, 11, 13, 21, 23, 27, 31, 33,
37