College Algebra
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MATH107_Q4_1.docxMATH 107 QUIZ 4 Instructor: Dr Jill Whealon
NAME: _______________________________
My signature indicates that I have completed this assignment myself, working independently and not consulting anyone except the instructor.
INSTRUCTIONS
· The quiz is worth 100 points. There are 13 problems. This quiz is open book and open notes . This means that you may refer to your textbook, notes, and online classroom materials, but you must work independently and may not consult anyone (and confirm this with your submission). You may take as much time as you wish, provided you turn in your quiz no later than the due date.
· Show work/explanation where indicated. Answers without any work may earn little, if any, credit. You may type or write your work in your copy of the quiz, or if you prefer, create a document containing your work. Scanned work is acceptable also. In your document, be sure to include your name and the assertion of independence of work.
· General quiz tips and instructions for submitting work are posted in the Quizzes module.
· If you need more room, just add it into the file.
· If you have any questions about the quiz, please ask on the Discussion Board or email me at [email protected]
·
1. (4 pts) Solve the inequality x2 9x and write the solution set in interval notation.
(No explanation required) 1. ______
A. [9, )
B. (–, 0] [9, )
C. (–, 9] [0, )
D. [0, 9]
(No explanation required)
A. (1, 5)
B. (–, –2]
C. (–, –2] (1, 5)
D. [–2, 1) (6, )
3. (4 pts) For f (x) = x3 – 2x2 – 7, use the Intermediate Value Theorem to determine which interval must contain a zero of f. (Show your work) 3. _______
A. Between 0 and 1
B. Between 1 and 2
C. Between 2 and 3
D. Between 3 and 4
4. (4 pts) Translate this sentence about area into a mathematical equation.
The area A of a regular pentagon is directly proportional to the square of the length s of its sides.
5. (8 pts) Look at the graph of the quadratic function and complete the table. [ No explanations required.]
|
Graph |
Fill in the blanks |
Equation |
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|
State the vertex:
____________
State the range:
_____________
State the interval on which the function is decreasing:
_____________ |
The graph represents which of the following equations?
Choice:____
A. y = –x2 + 2x – 1
B. y = –2x2 – 4x + 1
C. y = 2x2 + 4x – 1
D. y = x2 + 2x – 1
|
6. (12 pts) Look at the graphs below and complete the table for each one. (No explanation required)
|
Graph |
Graph A |
Graph B |
|
Is the degree of the polynomial odd or even? (choose one) |
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|
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Is the leading coefficient of the polynomial positive or negative? (choose one) |
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How many real number zeros are there? |
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(a) State the domain.
(b) Which sketch illustrates the end behavior of the polynomial function?
|
( vvv v )A.
|
( vvv v )B. |
( vvv v )C. |
( vvv v )D. |
Answer: ________
(c) State the y-intercept:
(d) State the real zeros:
(e) State which graph below is the graph of P(x).
GRAPH A. (below) GRAPH B. (below)
GRAPH C. (below) GRAPH D. (below)
(a) State the y-intercept(s).
(b) State the x-intercept(s).
(c) State the vertical asymptote(s).
(d) State the horizontal asymptote(s).
9. (8 pts) Solve the equation. Check all proposed solutions. Show work in solving and in checking, and state your final answer.
10. (8 pts) Which of the following functions is represented by the graph shown below? Explain your answer choice. Be sure to take the asymptotes into account in your explanation.
10. _____
A.
B.
C.
D.
11. (8 pts) For z = 4 – 2i and w = 7 + i, find z/w and simplify the final answer. Show your work.
12. (8 pts) Consider the equation 5x2 + 20 = 16x. Find the complex solutions (real and non-real) of the equation, and simplify as much as possible. Show work.
13. (10 pts)
The cost, in dollars, for a company to produce x widgets is given by C(x) = 5250 + 7.00x for
x 0, and the price-demand function, in dollars per widget, is p(x) = 45 0.02x for 0 x 2250.
The profit function for this scenario is
P(x) = 0.02x2 + 38x 5250.
(a) The profit function is a quadratic function and so its graph is a parabola.
Does the parabola open up or down? __________
(b) Find the vertex of the profit function P(x) using algebra. Show algebraic work.
(c) State the maximum profit and the number of widgets which yield that maximum profit:
The maximum profit is _______________ when ____________ widgets are produced and sold.
(d) Determine the price to charge per widget in order to maximize profit.
(e) Find and interpret the break-even points. Show algebraic work.
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