Math 1111                   Review                      Sections 1.1-1.3                    Ralston                           

 

ANSWER KEY

 

You may use your formula sheet and a TI-83 or equivalent calculator.  Sharing of calculators is not permitted

 

For questions 1-2, complete the table.   Use the resulting solution points to sketch the graph of the equation.  

 

1.   y = 3x - 6                                                  

                                                                                   

x

y

-1

 

-9

0

 

-6

2

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. 

                                                           

x

y

-2

 

8

-1

 

5

0

 

4

1

 

5

2

 

8

 

 

 

 

 

 

 

 

 

 

 

 

 

For questions 3-5, use the following table

 

 

U.S. Presidents and Their Vice Presidents

President (x)

Vice President (y)

George Washington

John Adams

John Adams

Thomas Jefferson

Thomas Jefferson

Aaron Burr

Thomas Jefferson

George Clinton

James Madison

George Clinton

James Madison

Elbridge Gerry

 

3.  Determine whether the relation is a function  NO, since Thomas Jefferson had 2 different VPs as well as James Madison

 

4.  State the domain of the relation. {George Washington, John Adams, Thomas Jefferson, James Madison}

 

5.  State the range of the relation.  {John Adams, Thomas Jefferson, Aaron Burr, George Clinton, Elbridge Gerry}

 

For questions 6-8, use the following list of ordered pairs.  Each ordered pair represents year as x and number of North Atlantic tropical storms and hurricanes as y.

 

{(1994, 7)  (1995, 19)  (1996, 13)  (1997, 7)  (1998, 14)  (1999, 12)  (2000, 15)  (2001, 15)  (2002, 12)}

 

6.  Determine whether the relation is a function. YES

 

 

7.  State the domain of the function. {1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002}

 

 

8.  State the range of the function.     {7, 12, 13, 14, 15, 19}  

 

 

For questions 9-, consider the following relation and its graph:   y =

 

                       

 

9.  Find the y-intercept of the relation.  Write answer as an ordered pair . (0,0)

10.  Does the given relation represent a function?  How do you know?   Yes, the graph PASSES VLT

11.  What is the domain of the function?  Write answer in interval notation. (-∞, ∞)

12.  What is the range of the function?  Write answer in interval notation. (-∞, ∞)

13.  Observe the graph (graphically).  Does the function appear to be even, odd, or neither? Odd

14.  Confirm your answer to question #13, algebraically.

            -y =(-x)3 -3(-x)

            -y =  - x3 + 3x

        -1* -y =-1*(- x3 + 3x)

            y =   x3 - 3x       same as original given equation, therefore, it is ODD.

15.  Determine the x-intervals for which the function is increasing.  Write answer in interval notation. (-∞, -1) or (1, ∞)

16.  Determine the x-intervals for which the function is decreasing.  Write answer in interval notation. (-1, 1)

17.   Identify the relative minimum(s), if any exist.  Write answer as ordered pair.  (1, -2)

18.   Identify the relative maximum(s), if any exist.  Write answer as ordered pair. (-1, 2)

19.  Observe the graph (graphically).   Estimate the zeros (x-intercepts) of the function.  Write answer as an ordered pair.   

        (-1.7, 0)  (0, 0)  (1.7, 0)

20.  Confirm your answer to question #20, algebraically.   Write answer as an ordered pair.

        y = x3 -3x

        y = x(x2 - 3)

So either  x = 0 or  x2 - 3 = 0

                                x2 = 3

                                x = square root of 3 and -square root of 3

(-sqrt 3, 0)  (0, 0)  (sqrt 3)

 

For questions 21-23, evaluate the given function at the given values of the independent variable and simplify.

 

           

 

 

21.   f(2) = 11/4

 

22.  f(0) = not possible, can NOT have zero in the denominator

 

23.  f( -x) =    2x2 +3 / x2