# Tutor.com Functions Session

##### Nov. 15, 2012

Session Transcript - Math - Calculus, 10/18/2012 3:47PM - Tutor.comSession Date: 10/18/2012 3:47PM
Length: 13 minute(s)
Subject: Math - Calculus

System Message
[00:00:00] *** Please note: All sessions are recorded for quality control. ***

Guest (Customer)
[00:00:00] i was supposed to find the inverse of this and determine its domain and range. i found the inverse but im having trouble determining the domain and range. Please help me?

Jose L (Tutor)
[00:00:03] Hi. Welcome to Tutor.com . I see your problem. Were you able to start it?

Guest (Customer)
[00:00:12] yes

Jose L (Tutor)
[00:00:16] ok great
[00:00:20] what do you have so far?

Guest (Customer)
[00:00:39] so i found the inverse. like i know the steps to get tht so ill write what i got

Jose L (Tutor)
[00:00:45] ok

Guest (Customer)
[00:01:18] thats what i got

Jose L (Tutor)
[00:01:32] let me check..working it here

Guest (Customer)
[00:01:41] ok

Jose L (Tutor)
[00:01:57] ok well it's +8 since the -8 is moved to the other side
[00:02:07] questions on that?

Guest (Customer)
[00:02:19] no i just wrote it wrong, sorry!

Jose L (Tutor)
[00:02:22] oh ok
[00:02:37] know how to find the domain?

Guest (Customer)
[00:03:14] umm do i just put x^2+8 is less than or equal to 0?
[00:03:20] like solve tht?

Jose L (Tutor)
[00:03:25] well we have an ..odd...root
[00:03:35] we can find roots of negative numbers
[00:03:40] when the root is odd
[00:03:44] for example
[00:03:50] cube root of -8 = -2
[00:04:03] so there are not restrictions for odd roots
[00:04:09] we can use any real number
[00:04:20] no* restrictions

Guest (Customer)
[00:04:28] ok]

Jose L (Tutor)
[00:04:32] questions on the domain?

Guest (Customer)
[00:04:38] no

Jose L (Tutor)
[00:04:44] know how to find the range?

Guest (Customer)
[00:04:53] no

Jose L (Tutor)
[00:05:04] if x=0
[00:05:12] what answer do you get?

Guest (Customer)
[00:05:17] 0?

Jose L (Tutor)
[00:05:45] 0^2 + 8 = ?

Guest (Customer)
[00:05:56] 8

Jose L (Tutor)
[00:06:00] cube root of 8 = ?

Guest (Customer)
[00:06:05] 2

Jose L (Tutor)
[00:06:25] what happens to y
[00:06:31] when x gets more positive
[00:06:40] for example x=1, then 10, then 100....

Guest (Customer)
[00:06:57] it increases

Jose L (Tutor)
[00:07:15] how about then x gets more negative
[00:07:20] hint: look at x^2
[00:07:31] so using x=-1, then -10, then -100...ect
[00:07:33] etc
[00:07:58] for example (-1)^2 then (-10)^2...

Guest (Customer)
[00:08:04] still increases

Jose L (Tutor)
[00:08:05] yes
[00:08:13] the same as x=1, 10, and so on

Guest (Customer)
[00:08:22] ok

Jose L (Tutor)
[00:08:23] so looking at the graph
[00:08:25] the range is what?
[00:08:30] look at the y-axis
[00:08:35] that's the hint

Guest (Customer)
[00:08:54] [2, infinity)

Jose L (Tutor)
[00:08:59] yes

Guest (Customer)
[00:09:06] oh thank God
[00:09:08] lol

Jose L (Tutor)
[00:09:08] questions on that?

Guest (Customer)
[00:09:14] i think i get it now

Jose L (Tutor)
[00:09:23] yes it's tricky sometimes
[00:09:30] just need to practice different problems
[00:09:34] to get used to it
[00:10:05] any questions?

Guest (Customer)
[00:10:06] yeah. i will so i have to graph? to figure out the range?

Jose L (Tutor)
[00:10:15] well you don't have to graph
[00:10:21] you can also make a table
[00:10:32] and another way is
[00:10:47] the domain of f(x)....is the range of inverse f(x)
[00:10:56] wait let me see
[00:11:55] yes

Guest (Customer)
[00:12:15] oh yay! i like tht better haha

Jose L (Tutor)
[00:12:23] yep so there are some methods
[00:12:31] in case you get stuck using one method
[00:12:34] try another

Guest (Customer)
[00:12:43] ok thank you so much Jose!

Jose L (Tutor)
[00:12:48] sure
[00:12:50]
[00:12:53] Thank you for using the service! Please fill out the survey and come back and use the service again!

Guest (Customer)
[00:12:55] bye