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Mathematics 10 Online
OpenStudy (rock_mit182):

For the following functions: \[f(x) =4\] ( is this a function?) \[x = (y+2)^{2}\] • State the domain and range for each of your equations. Write them in interval notation. • State whether each of the equations is a function or not giving your reasons for the answer.

OpenStudy (xapproachesinfinity):

are you asking if \(\large\sf\color{maroon}{ x=(y+2)^2 }\) is a function or f(x)=4?

OpenStudy (rock_mit182):

I'm asking for both expressions

OpenStudy (rock_mit182):

@jim_thompson5910 @ganeshie8

OpenStudy (rock_mit182):

@texaschic101 @Hero

OpenStudy (rock_mit182):

please help me out

OpenStudy (rock_mit182):

@iambatman

OpenStudy (xapproachesinfinity):

The first one is a function since it is a horizontal line y=4 Tge second you need to square root both sides And subtract 2 from both sides . Then determine whether it is a function or not

OpenStudy (rock_mit182):

@xapproachesinfinity what about the domain and range of a constant function ?

OpenStudy (rock_mit182):

\[\sqrt{x}-2 =y\] is equivalent to: \[x= (y+2)^{2}\]

OpenStudy (rock_mit182):

a mean for the fist expression we have: [0,infinity)

OpenStudy (rock_mit182):

but for the second i don't see any restriction..

OpenStudy (rock_mit182):

@xapproachesinfinity

OpenStudy (rock_mit182):

@radar @kropot72

OpenStudy (xapproachesinfinity):

The range of a horizontal line is a single point {4} Fot the other one u need plus and minus sign Be careful you are taking roots!

OpenStudy (xapproachesinfinity):

Oh I forgot the domain for the first one is all real numbers

OpenStudy (rock_mit182):

lets put this in a clearer way: f(x) = 4 --> domain infinity range 4 is a function cause the vertical line proof ?

OpenStudy (rock_mit182):

now for x = (y+2)^2

OpenStudy (rock_mit182):

\[\sqrt{x}-2 = y\] I've given a lot of thought... this expression wouldn't be the inve

OpenStudy (rock_mit182):

inverse of the original function ?

OpenStudy (rock_mit182):

@tkhunny @dan815 please someone help me out

OpenStudy (xapproachesinfinity):

So what do think, I have already given the answer above when I said + or - root x

OpenStudy (xapproachesinfinity):

Im on the phone otherwise I would explain to you in details

OpenStudy (rock_mit182):

mmm im just asking the reasons no the process..

OpenStudy (xapproachesinfinity):

The reason for plus or minus?

OpenStudy (rock_mit182):

instead if i draw \[y =\sqrt{x}-2\]

OpenStudy (rock_mit182):

|dw:1407439114368:dw|

OpenStudy (xapproachesinfinity):

No that's wrong! what im saying is tha y=+-rootx-2 try to draw this one. not y=rootx-2

OpenStudy (xapproachesinfinity):

abviously you will have rootx-2 graph and the reflection of it over the x axis it if you try the vertical line test then it is not a function

OpenStudy (rock_mit182):

NO it is not wrong , graph the expression{x = (y+2)^2 give us:

OpenStudy (rock_mit182):

|dw:1407439540352:dw|

OpenStudy (xapproachesinfinity):

ok now it good

OpenStudy (rock_mit182):

i think now you have seen my point

OpenStudy (xapproachesinfinity):

do the test if you draw y=+-rootx-2 you will have the same graph my friend because there is a reflection y=+-rootx-2 is two part y=rootx-2 and y=-rootx-2

OpenStudy (xapproachesinfinity):

it is the same thing doesn't matter how you approach it

OpenStudy (rock_mit182):

a ok that's all i needed to know

OpenStudy (rock_mit182):

but what about the vertical test line ?

OpenStudy (xapproachesinfinity):

if you do the vertical test you will see that is not a function

OpenStudy (xapproachesinfinity):

the vertical line cuts in more than one point

OpenStudy (xapproachesinfinity):

what is the domain of that relation?

OpenStudy (xapproachesinfinity):

So??

OpenStudy (rock_mit182):

so i cannot graph this in that way, what if i change the axis it would work out

OpenStudy (rock_mit182):

?

OpenStudy (xapproachesinfinity):

it is okay but just put in your mind that you change them

OpenStudy (rock_mit182):

|dw:1407440311560:dw|

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