Problem Set

Graphing Linear Functions


HIDE SOLUTIONS

 

1. Graph the function 3x + 2y = -4

 

Solution:

Step 1. Rewrite in the form y = a + bx and simplify

           

 

Step 2. Find a set of points which satisfy the equation and plot them.

 

let x = 0                       then 

 

let x = 2                       then   

 

let x = -2                      then

 

 

2. Graph the function 2x –y = -1

           

Solution:

Step 1. Rewrite in the form y = a + bx and simplify

 

            y = 1  + 2x

 

Step 2. Find a set of points which satisfy the equation and plot them.

 

            let x = 0                      

 

            let x = 2                      

 

            let x = 1                      


 

 

3. A copy shop can produce a course reader at a cost of $25 per copy. The monthly fixed costs are $10,000.

a. Determine the total monthly cost as a function of the number of copies produced.

b. Graph the total monthly cost function.

 

Solution:

 

a. Total cost  =  fixed cost  + variable cost

 

            C(q)    =  10,000  + 25 q

 

b. Find a set of points which satisfy the equation and plot them

 

q

C(q)

0

10,000

100

12,500

500

22,500

1,000

35,000

 


 

4. A chemical plant was found to be discharging toxic waste into a waterway. The state in which the chemical plant was located fined the company $125,000 plus $1,000 per day for each day on which the company continued to violate water pollution regulation.

a. Express the total fine as a function of the number of days in which the company remains in non-compliance.

b. Graph the relationship.

 

Solution:

 

a. Let d = the number of days in which the company remains in non-compliance

 

            f(d)  = 125,000  +   1000d

 

b. Find a set of points which satisfy the equation and plot them 

 

d

f(d)

0

125,000

1

126,000

5

130,000

10

135,000

 

 

 

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