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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"  smile

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"  smile

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.

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