College Algebra Functions



Use this template to insert your answers for the assignment.  Please use one of the four methods for showing your work (EE, Math Type, ALT keys, or neatly typed).  Remember that your work should be clear and legible.  

Problems need to include all required steps and answer(s) for full credit.  All answers need to be reduced to lowest terms where possible. 

1.  Is the following relation a function?  Why or why not?
          {(0, 1); (2, 6); (3, 4); (6, 1)}
2.  Is the following relation a function?  Why or why not?
3.  Given the function f(x) = 2x - 3, find three ordered pairs on the line.
4.  When f(x) = x+ 2x - 5, find f(-3), f(0), and f(4).
5.  Rewrite the equation 5x – 7y = 15 as a function of x.
In each of the following graphs, the bolded line represents a mathematical relationship between x and y.  Use the vertical line test to determine whether the relationship is a function.  Explain the reason for your conclusion.
10. What are the roots of the parabola?
   The roots are the x-values where the graph crosses the x-axis. These points occur at x = -2 and x = 3.
11.  What is the domain of the function?
The domain is the set of x-values that appear on the graph. For this parabola, any x-value will have a corresponding point on the graph. The domain then consists of the interval from negative infinity to positive infinity.
12.  What is the range of the function?
13.  If f(x) = x+2 and g(x) = 3x+1, then find (f · g) (2).
14.  If f(x) = 2x-3 and g(x) = x+3, then find (g · f) (5).
15.  If f(x) = -5x+7 and g(x) = 3x-5, then find (f - g) (4).
1.  A rug company uses the following function to calculate the cost of producing throw rugs.
2.  A ball is dropped from a height of 65 feet and modeled by the following function
3.  The profit for selling cases of paper is represented by p(x)= 3.65x – 7.80.  If x=2,000 and represents the cases of paper that are sold, find the profit.
4.  The time it takes a mechanic to complete an oil change is 7 minutes for each oil change and 10 minutes to set-up the station for the day.  Write a function where x represents the number of cars that get an oil change.  How long does it take to complete 50 oil changes?
5.  An electrician charges a trip fee of $40 and $65 per hour.  If h represents the number of hours he works on a job, write a function that represents this scenario.  Calculate the cost of a job that runs for 7 hours.
6.  The dosage (in mg) for Flea Alert is modeled by the function  where x represents the weight of the dog.  Find the dosage for a dog that weighs 50 lbs. and a dog that weighs 14 lbs.                                                                         
What is the difference between a relation and function? Discuss how to find the domain and range of a function. What test can you use to identify a function on a graph? Explain how to use it.
Create your own function and solve the domain and range. Discuss the shape of the graph.