# Parameterization of a graph

1. Mar 12, 2009

### intenzxboi

1. The problem statement, all variables and given/known data

Give a parameterization for the portion of the graph of xy = 1 for 1 < x < 3

i have no idea what it is asking
x=y

2. Mar 12, 2009

### Chaos2009

A parametric equation is an equation where x and y are expressed in terms of a third variable, usually t. I believe this is what it is asking. Also, xy = 1 does not become x = y.

3. Mar 12, 2009

### intenzxboi

so x+t, 1/y+t?

4. Mar 12, 2009

### Chaos2009

I think you should try looking for something along the lines of:
x = ...
y = ...

5. Mar 12, 2009

### intenzxboi

x=t
y=1/t

so (t, 1/t) 1<t<3

what do i do with this? prof didn't really go over an example like this

6. Mar 12, 2009

### sutupidmath

do you have any info for z?

7. Mar 12, 2009

### Dick

Set x=t, ok? So your first equation is x=t. What's y in terms of t?

8. Mar 12, 2009

### sutupidmath

this looks good. Is this in R^2 or R^3?

9. Mar 12, 2009

### intenzxboi

i did now what?

10. Mar 12, 2009

### Dick

z? Why z?

11. Mar 12, 2009

### intenzxboi

what do you mean r^2 or r^3?

12. Mar 12, 2009

### sutupidmath

No particular reason...its just that for some reason i thought we were working in R^3. But, this is not the case since,apparently, we are working in R^2.

13. Mar 12, 2009

### sutupidmath

I didn't write anywhere neither r^2 nor r^3.

14. Mar 12, 2009

### Dick

Seems so. Carry on.

15. Mar 12, 2009

### intenzxboi

so is that it?
x=t
y=1/t

so (t, 1/t) 1<t<3

16. Mar 12, 2009

### sutupidmath

yep!

17. Mar 12, 2009

### intenzxboi

thanks a lot guys!!

18. Mar 12, 2009

### Chaos2009

x = t? Really? You guys are boring. :rofl:

19. Mar 12, 2009

### sutupidmath

you could have also chosen y=t. or x=u, if you don't like "t's" in particular.

20. Mar 13, 2009

### Chaos2009

I meant you could have made x or y equal to any crazy function in terms of t and it would have still worked, but you guys chose the easiest one. I can't blame you if its for homework, though.