This is a blog for my second semester pre-calculus 30s students. Have a blast!

Monday, June 19, 2006

formulas??

I was wondering on the formula sheet for the exam is everything on there?? Or is there any specific ones we need to memorize?? Like the ones from the consumer unit and other ones too.
Just wondering. Thanks.

Thursday, June 08, 2006

GO FOR GOLD ANSWER KEY!!!!!

MC:

1) D 2) A 3) D 4) C 5) B 6) B 7) C 8) A 9) A 10) B 11) C 12) C 13) A 14) B 15) B 16) D
17) C 18) C 19) A 20) D

SA:

1) a) 9x^2 - 6x + 3 b) 9x - 4

2) x = -2 (-7 is not a solution when checked)

3) AT = 5 cm; angle TRD = 90 deg.; TD = 10; arc RD = 90 deg.; angle CTS = 70 deg.

4) check your TI-83

5) a) (4, 1) b) x = 4 c) D = (-inf, +inf) R = (-inf, 1] d) x = 3, 5 e) check TI-83

6) f_inv = (x-3) / 2

7) ommitted

8) a) 87 mills b) $6525

9) C = (-4, 5) r = 11

10) a) in class b) 2 c) 2

11) theta = 80.4 deg, 279.6 deg

12) x = (7 +- root(57)) / 4

LA:

1) ... 3x^2 - 33x - 78 = 0
3(x - 13)(x + 2) = 0
x = 13 (-2 is an extraneous root)

2) (tan x - 3)(tan x + 2) = 0

x = 71.6 deg, 116.6 deg, 251.6 deg, 296.6 deg

3) a) x = 1; y = -1; z = -2
(1, -1, -2)

b) (+- 9/4, +- root(175/16))

4) [-1,5] .... number line as well.

5) b = 51.4, 5.4

6) > lengths of sides are equal. (dist. formula)
> opposite sides have equal slopes. (slope formula)
> diagonals bisect each other. (mid point formula)

7) f(1) = 0

therefore..(x-1) is a factor

...after synthetic division....(x-3) & (x-2) are other factors

...roots = 1,2,3, y-int = -6 graph as well

8) Sales: (6000 - 200; Profit: (20 + x)

Max = (6000 - 200x)(20 + x)
...
...
= -200x^2 + 2000x + 120000
* h = 5

P = 20 + 5
= $25.00

9) Assume 2 = 1; given 3 = 1
1 + 2 = angle ABC
3 + 4 = angle ACB
1 + 2 = 3 + 4

therefore: angle ABC = angle ACB

...but given ABC not = angle ACB

therefore 2 does not = 1

10) a) * shift 2 right, up 1 of y = 1/x; VA: x = 2; HA; y = 1; graph using TI-83

b) VA: x = 3, -3 HA: none; y-int: x = -1/9; sketch graph using TI-83

11) r = 7 using (distance from pt to line formula)
C = (1,5)

* therefore equation: (x - 1)^2 + (y - 5)^2 = 49

*