Notes:
3/7 3/9 3/14/00 3/16

### 3/7

I. In the book, pg 177, #40, 42, 46, 52
II. Given:
width = x
length= one less than double the width
height = 6 cm
Write volume function
Write surface area function  Go to Answers
II. Write the distance function if:
The initial distance is 10 cm and the object travels 25 cm/sec.
At the start, time zero, t0, the distance is 10. The "y-intercept" is 10.
The object travels 25 cm/sec. so after 1 second, the object has traveled 25 cm so the slope is 25/1 or 25.
The equation is linear. It is d(t) = 25x + 10.

### 3/9

I. Please do: pg 189 # 67, 68 then
II. Write the area formula given:
III. Solve algebraically:
1.)     x + 2 = 0
2.)     x + 2 = - x + 3
3.)     x² - 5x - 14 = 0

IV. Solve x + 2 = - x + 3 graphically:
When the two curves cross, they are equal. The x-value of this ordered pair is the solution to the equation.
V. Solve on the calculator using the CALC (83) or MATH (85, 86) menu.
85:
1st: In [GRAPH] in y(x)= enter each expression as a function.
2nd: Press [EXIT] then [MORE] to find the [MATH] menu.
3rd: Press [MATH] then [MORE] then [ISECT] for intersect.
4th: On the graph, move the curser till the spider is sitting on one function.
5th: Press [ENTER]
6th: Move the curser/spider to the other function.
7th: Press [ENTER] to solve.

83:
1st: In y= enter each expression as a function.
2nd: Press [CALC] for calculus (above [TRACE]).
3rd: Press
Also enter the variable, x, and
a constant or seed value or guess to start the computation.
4th: Press [ENTER] to solve.

VI. Solve on the calculator using SOLVER (82, 83) or SOLVE (85, 86).
85:
1st: Press SOLVER (above GRAPH)
2nd: Enter the equation
Ex. equ:leftside = rightside
Ex. equ:x + 2 = - x + 3 (The = is above [STO>].
3rd: Press [ENTER]
4th: Be sure the curser is on the line with the varible you want.
5th: On the soft keypad, press [SOLVE].

82:
1st: Rewrite the equations so one side or member is 0.
2nd: Press [MATH] then [0:Solver(]
3rd: Enter the expression in step 1 as part of the argument of the Solver function.
Also enter the variable, x, and
a constant or seed value or guess to start the computation.
Ex. Solve(expression, variable, seed
Ex. Solve(x + 2 + x - 3, x, 5
4th: Press [ENTER] to solve.
83:
1st: Rewrite the equations so one side or member is 0.
2nd: Press [MATH] then [0:Solver(]
3rd: Press the curser to get up to the equation line.
4th: Type the expression from step 1 after the =.
5th: Press the curser down to the line with the variable you wish to find.
6th: Press [SOLVE] ([ALPHA][ENTER]) to solve.

VII. Solve on the calculator using POLY (85, 86).
85:
1st: Press POLY (above PRGM)
2nd: Enter order 2 for 2nd degree, 3 for 3rd degree, ...
3rd: Enter each coefficient as pictured in the equation.
4th: On the soft keypad, press [SOLVE].

VIII. Solve algebraically.
1.)     x + 5 = 5 + x
2.)     x + 5 = 6
3.)     x + 5 = 7 + x

IX. Homework: ch 2.1 and 2.2.

### 3/14

II. Solve example problems in chapter 2 section 4 and solve:
x2 + 1 = 0
III. Vocabulary:  discriminant  real number  rational number
IV. Calculator Computation Technique
The [ENTRY] or [2ND][ENTER] key is used to recall the last entry so that it may be edited and a similar computation completed w/ few keystrokes.
Ex. Solve x2 + 8x + 12 using the quadratic formula.
1st:   Type (-8+ (((8)2-4(1)(12)))/(2*(1)) and [ENTER]
2nd: The result is -2
3rd: Press [ENTRY] or [2ND][ENTER].
4th: Use the curser to move & type over the + sign.
(-8- (((8)2-4(1)(12)))/(2*(1))
5th: Press [ENTER] to obtain the other root.
6th: The result is -6.

### 3/16

I. In the book, pg 212 #36, 53, 59
II. Sketch
1. y = |x+3|-2
2. y = |x-6|
III. Solve
3. |x+3|-2 = |x-6|
IV. Expand
4. (x+3)2
5. (x + a)2
6. (2 - x)2
7. (x + 2)2
V. Solve
8. (2x + 7) - x = 2
8. x4 - 1 = 0     Answer
VI. Vocabulary
Look for extraneous roots -- answers which solve the final equation but not the original equation.

3/7/00:
V(x) = (lenght)(width)(height)
V(x) = (2x -1)(x)(6)

S(x) = total area of the five-sided box.
S(x) = 1(length)(width) + 2(width)(height) + 2(length)(height)
S(x) = 1(2x - 1)(x) + 2(x)(6) + 2(2x - 1)(6)

A(x) = (left) + (right) = 16x + 6x = 22x
A(x) = (top) + (bottom) = 14x + 8x = 22x
A(x) = (big) - (little) = 28x - 6x = 22x
1-3.
4. x2 + 3x + 9
5. x2 + 2ax + a2
6. 4 - 4x + x2
7. x + 2 x + 4
8. x = 1

Last page     Next page     asquared@mathnstuff.com

http://www.mathnstuff.com/math/precalc/prec4.htm     Revised: 4/30/00