Piecewise-defined function

  • Thread starter Rusho
  • Start date
  • #1
24
0
A phone company offers a deal by which a long distance phone call costs .99 cents for the first 20 minutes and .07 per minute thereafter. Write a piecewise-defined function for the cost C of making a phone call that lasts x minutes.

So I did this:


f(x) { .99(6) 0<= x
.99(20) 0=> x >= 20

Not a clue what I'm doing...:mad: :mad: :mad:
 

Answers and Replies

  • #2
VietDao29
Homework Helper
1,423
2
Okay, say you make a x-minute phone call (x <= 20), i.e a phone call that lasts no longer than 20 minutes. How much will you have to pay if you know that each minute costs you .99 cents?
------------------------
If you make a y-minute phone call (y > 20), i.e a phone call that lasts more than 20 minutes. How much will you have to pay for the first 20 minutes? How much will you have to pay for the (y - 20) minutes last? Then do you know how much will you have to pay for that whole y-minute phone call?
------------------------
Your function will look like this:
[tex]f(x) := \left\{ \begin{array}{l} ... , \quad \quad \mbox{if } 0 \leq x \leq 20 \\ ... , \quad \quad \mbox{if } x > 20 \end{array} \right.[/tex]
Can you go from here? :)
 

Related Threads on Piecewise-defined function

  • Last Post
Replies
2
Views
4K
  • Last Post
Replies
4
Views
530
  • Last Post
Replies
3
Views
1K
Replies
6
Views
726
  • Last Post
Replies
3
Views
2K
Replies
8
Views
47K
  • Last Post
Replies
3
Views
682
Replies
1
Views
3K
Replies
5
Views
5K
Replies
2
Views
824
Top