13. Write a translation rule that maps point D(7, –3) onto point D'(2, 5).

14. Triangle ABC has coordinates A(1, 4); B(3, –2); and C(4, 2). Find the coordinates of the image A'B'C' after a reflection over the x-axis

Question

13. Write a translation rule that maps point D(7, –3) onto point D'(2, 5). 




14. Triangle ABC has coordinates A(1, 4); B(3, –2); and C(4, 2). Find the coordinates of the image A'B'C' after a reflection over the x-axis

3mar · Answer

May I help?

electronia · Answer

If you can than thats great. :)

electronia · Answer

There is not a graph with this one, just telling you that. :)

3mar · Answer

Ok
I see..
what is the difference between x-coordinates of the two points?

electronia · Answer

Well im not sure, but is it ok if I clarify my answer with you?

3mar · Answer

Yes Of course.

electronia · Answer

Here it is, is this right?

563blackghost · Answer

I agree with your answer for 13 :)

electronia · Answer

Ok, great! and for 14 maybe The new coordinates are 
A(1, -4) B(3,2) and C(4,-2). So since it's reflecting over the X axis you keep the X coordinates the same and the Y coordinates change. If the number is negative you make it a positive, if it's positive you make it a negative

563blackghost · Answer

Reflection over the x-axis is...

$\huge\bf{(x,y) \rightarrow (x,-y)}$

So if we apply we get `(1,-4), (3,2), and (4,-2)` so I agree :)

3mar · Answer

$$\Huge (x',y')=(x-5,y+8)$$

electronia · Answer

Oh, so im right. Thanks you two! Ill fan both of you. :)

563blackghost · Answer

Nicely Done @3mar :)

3mar · Answer

$$\Huge\color{darkorange}\checkmark$$

You are correct!

3mar · Answer

These are kinds of reflections: 
Reflection across x-axis:		(x, y) > (x, -y)
Reflection across y-axis:		(x,y) > (-x, y)
Reflection over origin:		(x,y) > (-x,-y)
Reflection over line y=-x:		(x,y) > (-y,-x)