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Find the image of P(–2, –1) after two reflections; first Ry=5 and then Rx=1.
A. (–2, –1)
B. (–1, –6)
C. (4, –9)
D. (1, –5)
 8 months ago
 8 months ago
Find the image of P(–2, –1) after two reflections; first Ry=5 and then Rx=1. A. (–2, –1) B. (–1, –6) C. (4, –9) D. (1, –5)
 8 months ago
 8 months ago

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e.mccormickBest ResponseYou've already chosen the best response.2
So the Ry=5 and Rx=1 are the lines you need to reflect across?
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Those are the reflections
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
A reflection is usually over a line.... so I want to make sure that is the notation you are using.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
http://www.mathopenref.com/reflect.html Like it says there, "A transformation where each point in a shape appears at an equal distance on the opposite side of a given line  the line of reflection. " So, start by just doing a rough sketch. Does not need to be exact, but you need to find where the dot and line would be and how far the line is from the dot. If you can do that with math, great! But a sketch can help.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Okay, but i dont understand what i have to do...
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Well, it needs to be an equal distance from the line on the other side of the line.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Where did the line come from????
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Ry=5 \(\leftarrow\) that is the line part.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Let me show you an example.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Okay...Just show me with this one
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
If I work this that is me giving you an answer. If I work an example you can follow the process and answer your own homework. Lets say I take this random dot: dw:1376455485961:dw And lets say I have Ry=1, so the line where every Y is 1.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
dw:1376455572591:dw
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Well, im really lost man...So i wouldnt even get it
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
That is an example already, im just doing a text review for before i take it. so it doesnt count
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
The important measure is the distance from the dot to the line. dw:1376455620753:dw Because I need to put the reflection the SAME DISTANCE on the other side of the line.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
dw:1376455677255:dw
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Do the distance is the number in the equation?
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Let me try to do mine...one sec
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
The distance is the measure from your point and the line.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yours is done twice.... so see what you get for the first step and I can check it. Then the second step.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
dw:1376455841757:dw
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
OK, that is a good (2,1).
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
dw:1376455914360:dw
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Now what do i do exactly?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
OK, so what is the measure of the distance between your dot and the line? dw:1376456012468:dw
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Not quite. Tewo problems. This is change in y, not x, and distance is always positive.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yes. So your point is 4 above the line. That means the reflection must be 4 BELOW the line!
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
The line is at 5. So 4 below 5.... or 54=?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Above is +, below is . Similarly, to the left of is , to the right of is +. Has to do with the Cartesian (xy) plane rules.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yes. That means the X is the same and the Y is now 9. So, the point after 1 translation is at (2,9). dw:1376456612998:dw
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Now you have the line Rx=1 to do the second reflection over.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
dw:1376456678313:dw
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
dw:1376456695550:dw
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
So, how far this time?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
\(\large\ddot\smile\)
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
so the point would me three to the right?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yes, 3 to the right of 1. And yep, that is it. (4,9).
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
wait im gonna see if it matches...
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Now, once you get good at the math, you should not need a sketch, but if yuou are ever in doubt, the rough sketch is there to help!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Okay, the textbook just didnt really explain it
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
The thing I think most people mes up here is the line.... because x=0 is the y axis, and y=0 is the x axis. So they give you a y line but you draw it the same way as the x axis and that can be confusing!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
yea, thats the right answer! thanks:)
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Can you help with some other questions that i dont get?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Probably. I can explain it the same basic way I always do and hopefully it works like this and you get it!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
What composition of rigid motions and a dilation maps EFGH to the dashed figure? https://study.ashworthcollege.edu/access/content/group/45b8c516100846d7aa1dbb9b62c786ff/geometry_exam_9_files/mc0201.jpg
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
OK. Dilation is going to be the size change. The rigit motion will get it from one place to the other.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
It is probably easiest to do the dilation first. That will be some multiplication number. It is a ratio of the sides.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
For example, this would be a dialation by 3..... dw:1376457753408:dw So start by finding how long the sides of both rectangles are.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
wait is the answer D2*T<0,6>
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
2x the size, so yah, a dialation of 2. I didn't do the rest yet, but that would probably do it.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Really??? woooohoooo
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Hmmm.... 6.... is that enough on the translation?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Well, lets look at this real quick: dw:1376458028692:dw Now you need to double the size.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
The dialation is times 2?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
dw:1376458060944:dw OK, that makes them reflections of each other.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
So now, one of two things needs to happne.... It either needs to be reflected over the x axis, OR, corner H needs to go all the way down to the bottom corner. dw:1376458143764:dw
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
so its shifted down 6
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Well, is that 6? That bottom corner is at 9....
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
or 10, actually.... counted wrong.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
So it has to go from 2 above to 10 below... so....
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
so uhm...It would be 11?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yep! So 2D, T\(\langle 0,12\rangle\) is more like it.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
that isnt one of my options
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Hmmm.... AH.... OK... the dialaion is probably also changing the translation! \(2\langle 0,6\rangle = \langle 0,12\rangle\)
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
So my bad. Looks like you did have it right.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
YUS:) thanks though!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
The hexagon GIKMPR and FJN are regular. The dashed line segments form 30° angles. What is r(240drg,0)(G)
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Well, the good news is you should understand the why a bit better! By exploring these, it lets you understand the why of it all....
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Hmmm..... I have not seen that form of question.... my geometry was a while back, and they have changed some of the things they do... Do you know what it is looking for, any terms? An angle?
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Thats really all i understand...
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
r is usually a radius.... but there is no distance....
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
I think r is the point?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Is it R and not r?
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Thats the problem..
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
hmmm..... Well, 240/30=8 segments.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
so 8 to the left or right?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Well, if r is right... but that would be a guess on my part. Right 8 of G? I would need to see the reference to know they type of peoblem to get this one.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
So would it be K???
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
I would only be guessing without the book and chapter.
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Okay...Well for me thats better then nothing!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
The vertices of a triangle are P(–8, 6), Q(1, –3), and R(–6, –3). Name the vertices of \[R _{y=x}(PQR)\]
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Is that a reflection over the y axis?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
AH HA! Found a reference! http://www.regentsprep.org/Regents/math/geometry/GT6/composition.htm
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
The composition part does not matter here.... the \(R_y\) part is reflection over the y axis!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
So just make it the other sign?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
And even better! http://www.regentsprep.org/Regents/math/geometry/GT5/reviewTranformations.htm
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Would the first point be (6,8)
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
OHHHH!!! MAKES SENSE!
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Amazing what finding a reference to the symbols can do!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
YEA! Thanks so much man!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
Write a sequence of rigid motions that maps ab and xy
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
LAST ONE AND I WILL UNDERSTAND GEOMETRY!
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
That composition part also confirms what we talked about with the <0,6> becoming <0,12>. The SECOND part of the compositon happens first!
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
the second part is (AB=XY)
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Are those seperate calculations for those two?
 8 months ago

OpenSessameBest ResponseYou've already chosen the best response.0
The top doesnt matter just look at the lines
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Yah, well, then that is some sort of what? Rotation, reflection etc?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Remember that A is going to X and B is going to Y..... should be a huge clue.... YES! Some sort of reflection.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
So, you just need to find the line they are reflected over.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
It would be half way between them.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Are they both the same distance from x=0?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Did you count the distance from 0 to X and 0 to A?
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
Take a second look.... they are not the same.
 8 months ago

e.mccormickBest ResponseYou've already chosen the best response.2
You want the line half way between. So take the distance between the two points and divide by 2. It will be that far to the left of the right most line, and right of the left most line.
 8 months ago
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