Tuesday, December 9, 2008

Tuesday, December 9

College Algebra - We discussed Sec. 5.7 - the ambiguous case of SSA. HW for Wednesday - Complete pg. 324 #11 - 16 all and #20 - 28 even.

Accl. Geometry - We worked through Sec. 7.2 -properties of isometries. HW for Wednesday - Read Sec. 7.2 and complete pgs 380 - 382 #1 - 12 and #15 - 18.

HW answers from Monday - pgs 372 - 375
1) Rigid; reflected but the size and shape do not change
2) Nonrigid; the shape achanges
3) Nonrigid; the shape stays the same but the size changes

4) Reflect --> "flip" the figure over the given line
If the given line is the y-axis, then every point (x, y) maps onto the point (-x, y)

5) Rotate --> "spin" the figure around the given point
If the given point is the origin, then every point (x, y) maps onto the point (-x, -y).

6) Translate --> "slide" the figure in the direction of the given arrow
If the given vector is horizontal and has a length of 3 units, then every point (x, y) maps onto the point (x+3, y).

7) exapmle - a boat moving acorss a lake
8) example - a ferris wheel
9a) example - fold the paer so the the two images match up; crease the paper along this fold; the crease is the reflection line
9b) example - creat a segment that connects two corresponding points (one from each figure) and the construct the perpendicular bisector of this segment
10a) example - extend the three horizontal segments onto the other side of the reflection line, measure the distance form the reflection line to various critical points in the orignal figure and then locate the images of these points on the horizontal lines on the other side of the reflection line
10b) shaded square is now in the lower right, the shaded circle is now in the lower left, and the shaded triangle is located to the right of the center line

11) the circle should face due left, the pie shape should face the upper right, and the equal sign should face the lower right
12) 1 reflection
13) 4 reflections and 4 rotations
14) 1 reflection

19) P(-a, b); Q(-a, -b); R(a, -b)
16), 17), 18), and 20 - We will discuss the other problems in class tomorrow.


pg 289-290
1) - 3) - we will discuss in class tomorrow
4) y = -x + 2
5) y = -(6/13)x + (74/13)
6) y = x + 1
7) y = -3x + 5
8) y = (2/5)x - (8/5)
9) y = 80 + 4x
10) y = -3x + 26
11) y = -(1/4)x - 3
12) y = (6/5)x
13) y = x + 1
14) y = -(2/9)x + (43/9)


Pg 348
1) (-0.5, 3)
2) (-3, -3)
3) (0.4, 3)
4) (7, -2)
5) infinite solutions
6) no solution
9a) Plan A: y = 4x + 20 and Plan B: y = 7x; x = 6 hr 40 min and y = $46.67
9b) The point of intersection shows where the two plans have the same cost
9c) Plan B; $50 will get you 75 hours with Plan A

No comments: