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Topic review (newest first)
- anonimnystefy
- 2012-12-04 20:52:11
bob bundy wrote:
Thank you Stefy.
And there was me, about to award you the "Teacher of the Month Award"
Bob
I hope you are kidding.
Hi daydoe12
I'm male, not female...
- bobbym
- 2012-12-04 16:05:51
Hi daydoe12;
You have -2 -> 3 and 8 -> 5 so call x=-2 and y =3 in the first equation and x = 8 and y = 5 in the second.
When you solve that you get m = 1/5 and b = 17 / 5. Now plug in to the first equation.
- daydoe12
- 2012-12-04 14:30:49
I have tried finding the form using the y=mx+b formula and i cant figure out how she got x+17/5
- bob bundy
- 2012-12-01 03:45:41
Thank you Stefy.
And there was me, about to award you the "Teacher of the Month Award" 
Bob
- anonimnystefy
- 2012-12-01 01:48:15
Hi daydoe12
Bob explained very well in post #9. I don't think I could any better at explaining it.
- daydoe12
- 2012-11-30 14:30:39
anonimnystefyLegendary Memberb how did you arrive at that answer
- bob bundy
- 2012-11-29 18:59:53
Stefy just looked for a formula of the form y = mx + c so that when x = -2, then y = 3, and similarly when x = 8, y = 5.
My answer used a similar idea but I think his is the right way.
If you think about the straight line graph this produces, every point between -2 and 8, will map onto every point between 3 and 5
And the mapping is reversible.
To prove it, you'd have to show the mapping is 1:1 in both direcctions, and that a point inside the first interval maps to a point inside the resulting interval.
Bob
- daydoe12
- 2012-11-29 15:39:02
how did you arrive at that answer
- anonimnystefy
- 2012-11-28 08:16:14
Doesn't matter. I hope we solved the OP's problem.
- bob bundy
- 2012-11-28 08:10:52
Which was ... ?
Bob
- anonimnystefy
- 2012-11-28 08:08:20
Hmmm... I thought there was another reason.
- bob bundy
- 2012-11-28 06:43:44
Good answer, Stefy.
I think yours is correct and I have misunderstood what is wanted.
I'll leave the post as a reminder to me to read the question!
Bob
- anonimnystefy
- 2012-11-28 01:18:38
Hi daydoe12
- bob bundy
- 2012-11-27 20:13:05
hi daydoe12
Welcome to the forum.
How about
Bob
- daydoe12
- 2012-11-27 13:40:18
Define a bijection between the sets [-2,8] and [3,5]. Prove your function is actually a bijection.