Respuesta :
The coordinates of the point (-9, 4) after a 90 degree rotation followed by a translation 3 units right are (8,9) (for clockwise rotation) and (0,-9) (for counterclockwise rotation)
How does rotation by 90 degrees changes coordinates of a point if rotation is with respect to origin?
Let the point be having coordinates (x,y).
- Case 1: If the point is in first quadrant:
Subcase: Clockwise rotation:
Then (x,y) → (y, -x)
Subcase: Counterclockwise rotation:
Then (x,y) → (-y, x)
- Case 2: If the point is in second quadrant:
Subcase: Clockwise rotation:
Then (x,y) → (y, -x)
Subcase: Counterclockwise rotation:
Then (x,y) → (-y, x)
- Case 3: If the point is in third quadrant:
Subcase: Clockwise rotation:
Then (x,y) → (y, -x)
Subcase: Counterclockwise rotation:
Then (x,y) → (-y, x)
- Case 4: If the point is in fourth quadrant:
Subcase: Clockwise rotation:
Then (x,y) → (y, -x)
Subcase: Counterclockwise rotation:
Then (x,y) → (-y, x)
- Case 5: For points on axes
You can take that point in any of the two surrounding quadrants. Example, if the point is on positive x axis, then it can taken as of first quadrant or fourth quadrant.
- Case 6: On origin
No effect as we assumed rotation is being with respect to origin.
For this case, the point (-9,4) (present in second quadrant) is rotated by 90 degrees.
This rotation can be either clockwise, or counterclockwise.
Thus, for each case, we have:
- case 1: Clockwise rotation:
Then (x,y) → (y, -x), therefore, (-9,4) → (4, 9)
- case 2: Counterclockwise rotation:
Then (x,y) → (-y, x), therefore, (-9,4) → (-4, -9)
Now, when shifting to right by 4, that means, we're making no changes vertically, but old x-coordinates are increased by 4 to make them shift to right side as value of x increases as we go more and more to the right side with respect to the origin and in defaultly oriented cartesian space.
Thus, we have:
case 1: Clockwise rotation:
After translation of 4 units right:
(4, 9) → (4+4, 9) = (8,9)
- case 2: Counterclockwise rotation:
After translation of 4 units right:
(-4, -9) → (-4+4, -9) = (0,-9)
Thus, the coordinates of the point (-9, 4) after a 90 degree rotation followed by a translation 3 units right are (8,9) (for clockwise rotation) and (0,-9) (for counterclockwise rotation)
Learn more about rotation of a point with respect to origin here:
https://brainly.com/question/18856342
