Find the coordinates of the point (-5,7) when it is reflected across the line y=11.

Question

anonymous · Answer

Use mid point formula.

anonymous · Answer

But don't you need more than one coordinate?

anonymous · Answer

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

anonymous · Answer

you know x1 and y1 find x2 and y2

anonymous · Answer

Did you get it .

anonymous · Answer

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.

anonymous · Answer

did you get the idea behind mid point

anonymous · Answer

Yes I do!

anonymous · Answer

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

anonymous · Answer

now use x1=-5 and y1=7

anonymous · Answer

now use the formula that I have already posted

anonymous · Answer

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

anonymous · Answer

Nevermind, let me resolve quick.

anonymous · Answer

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