Measurement: find coordinates of image of P under rotation

[archy]

3) In the xy-plane, line l has equation y = -x. Point P lies on l and has coordinates (-2,2). If l is rotated counterclockwise 45degree about the origin, what will be the coordinates of the image of P under this roation?

 

[arthur ohlsten]

Re: Measurement

x=-2 y=0
I believe this is what is wanted
The line becomes the x axis
Arthur

 

[archy]

Re: Measurement

The answer is -2squareroot 2, and zero. Can you let me know the step by step solution. Thanks

 

[Mrspi]

Re: Measurement

If the line y = -x is rotated counter-clockwise 45[sup:2x64lk1z]o[/sup:2x64lk1z], it will indeed coincide with the x-axis.

Sketch the original line y = -x, and locate the given point (-2, 2) on that line. How far is the point from the origin? (use the distance formula). After the rotation of 45[sup:2x64lk1z]o[/sup:2x64lk1z] in the counter-clockwise direction, the image of that point will be on the negative x-axis, the same distance from the origin that the original point was from the origin.

You've asked a variety of questions covering a variety of topics....and have not shown one bit of work you've done on your own. I wonder if this is a test of some sort.......

 

[archy]

Re: Measurement

Yes - I am a studying for a state test. I encouter some issues since my background is not in mathematics.