A triangle has vertices W (-4,7), Q (-1,-1) and Z (-7,-2). Apply rotation mapping rules to find the coordinates of W' after a 90-degree rotation about the origin.

1 answer

To find the coordinates of the point W' after a 90-degree counterclockwise rotation about the origin, we can use the rotation mapping rule for 90 degrees, which states:

\[ (x, y) \rightarrow (-y, x) \]

Given the coordinates of point W as (-4, 7), we can apply the rotation rule:

  1. Take the y-coordinate (7) and make it the new x-coordinate.
  2. Take the x-coordinate (-4) and make it the new y-coordinate, but negate it.

So:

  • The original coordinates of W are (-4, 7).
  • After applying the rotation:
    • New x-coordinate: -y = -7
    • New y-coordinate: x = -4

Thus, the coordinates of W' after a 90-degree rotation about the origin are:

\[ W' = (-7, -4) \]