Dilating a point from the origin
A dilation centered at the origin changes a point’s distance from the origin by a scale factor, but keeps it on the same line through the origin. For a point ((x,y)), the image after dilation by factor (k) is ((kx,ky)).
Steps
- Identify the original coordinates of the point.
- Multiply both coordinates by the scale factor.
- Simplify the result if needed.
Example pattern
If the point is ((3,-2)) and the scale factor is (4), then the dilated point is:
[
(4\cdot 3,,4\cdot (-2))=(12,-8)
]
Quick check
- The new point should lie on the same ray from the origin as the original point.
- If the scale factor is greater than 1, the image is farther from the origin.
- If the scale factor is between 0 and 1, the image is closer to the origin.
- A negative scale factor places the image on the opposite side of the origin.
Use the coordinate multiplication rule carefully, and then verify the point’s position relative to the origin.