milliex51 3 years ago The cost in dollars, C(d), to rent a houseboat during July to August from a certain company is given by C(d) = 120d + 100, where d is the number of rental days. a) Why does the 100 represent the fixed cost and the independent variable of the number of days? b) State the domain and range: Why is the domain: 0 ≤ d ≤ 62, range: 100 ≤ C ≤ 7540?

1. liliy

a) independent means that it will not be changed no matter what, so in every case no matter how many days you rent it. you will always have to add 100 . that is why its independent.

2. milliex51

Because when I graphed the function it is no where 62 and 7540. But I do know that from July to Agusut = 62 days and 120(62)+100 = 7540.

3. milliex51

ohh, i see.

4. liliy

july and aug have 31 days each so together its 62 days. so you can rent for a range between 0 adn 62 days.when you plug in those numbers you get the y values

5. milliex51

what do you mean when I plug in those numbers?

6. liliy

well in a simple equation we have y=x+.... so the 0 to 62 are the numbers you would put in for the x and finish the equationto find the range of the y.

7. milliex51

i still don't get it :(

8. liliy

in your equation:C(d) = 120d + 100, the d is the"x" and the C(d) is the y. so when you put in 0 you have C(d)=120*0+100. and you get C(d)=100. then plug in 62 day.: C(d)=120*62+100.cC(d)=7540::) so the smallest amoiunt was 100 and the largest amount was 7540

9. milliex51

ohhhh, i see. But how about x?

10. liliy

so x represnts thedays you can rent. as i said before:how many days can someone rent?

11. milliex51

62 days so from 0 to 62?

12. liliy

yup

13. milliex51

ohh, thank you :)

14. liliy

np