Question

Mary Beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. Examine the steps to determine whether she made an error. M (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. Switch the x- and y-coordinates: (6, –3) 2. Multiply the new x-coordinate by –1: (6(–1), –3) 3. Simplify: (–6, –3) .

Answer 1

M (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x)

1. Switch the x- and y-coordinates: (-6, 3) <-- there was a mistake.

2. Multiply the new x-coordinate by –1: (-6*(-1), 3)

3. Simplify: (6, 3).

Answer 2

Answer with explanation:

To find the coordinate of point ,which has been rotated by 90° in Counter clockwise Direction.

We have to follow following Procedure to find the coordinate of point after 90° in Counter clockwise Direction.

Coordinates of point =(x,y)

When it is rotated in counterclockwise direction,the coordinate of image will be = Interchange , x and y coordinate and put negative sign before abscissa,which will be= (-y, x).

So, point (3,-6) when rotated in counterclockwise direction, the coordinates of image will be = ( -(-6),3)=(6,3)

So,she made an error in step, while switching, that is , (x,y)→(-y,x),but ,(3,-6)→has been interchanged to (6,-3) which is incorrect.It should be, (6,3).

Step 1 is incorrect.