## cassidyohrt Group Title Find the coordinates of the point (-5,7) when it is reflected across the line y=11. one year ago one year ago

1. punnus Group Title

Use mid point formula.

2. cassidyohrt Group Title

But don't you need more than one coordinate?

3. punnus Group Title

mirror being mid point of the line joining the two points. $\left\{ -5,11 \right\}$ now $-5=\frac{x2-x1 }{ 2 }$ and $11=\frac{ y2-y1 }{ 2 }$

4. punnus Group Title

you know x1 and y1 find x2 and y2

5. punnus Group Title

Did you get it .

6. cassidyohrt Group Title

I completely understand what you're saying, but I honestly have no idea how to solve for x2 and y2. I remember learning this, but I haven't used it in 2 years.

7. punnus Group Title

did you get the idea behind mid point

8. cassidyohrt Group Title

Yes I do!

9. punnus Group Title

Then take the given point as the first point in the case i.e (-5,7)

10. punnus Group Title

now use x1=-5 and y1=7

11. punnus Group Title

now use the formula that I have already posted

12. cassidyohrt Group Title

Wait, so wouldn't it be (-5,-7)?

13. cassidyohrt Group Title

Nevermind, let me resolve quick.

14. punnus Group Title

did you get is answer as (-5,15). If not I can give us an another approach