Carcass wrote:
Point A ( 4, 6) lies on a line with slope \(- \frac{3}{4}\) Point B lies on the same line and is 5 units from Point A. Which of the following could be the coordinates of Point B?
Indicate all such coordinates.
A. (− 1, 1)
B. (− 4, 12)
C. (8, 3)
D. (1, 10)
E. (0, 9)
First sketch the given information:
Attachment:
Point A ( 4, 6) lies on a line with slope-1.png [ 8.38 KiB | Viewed 7804 times ]
Since the slope (rise/run) of the line is -3/4, for every 3 units we move UP, we move 4 units to the LEFT (alternatively, we can say for every 3 units we move DOWN, we move 4 units to the RIGHT)
Attachment:
Point A ( 4, 6) lies on a line with slope-2.png [ 10.91 KiB | Viewed 7790 times ]
Notice that we end up with a RIGHT triangle with legs of length 3 and 4, which means the hypotenuse must be length 5.
So, the point (0, 9) is on the line AND it is 5 units from the point (4, 6)
Likewise, if we start from (4, 6) and move 3 units DOWN, and 4 units to the RIGHT, we get the following:
Attachment:
Point A ( 4, 6) lies on a line with slope-3.png [ 10.9 KiB | Viewed 7741 times ]
Once again, we end up with a RIGHT triangle with legs of length 3 and 4, which means the hypotenuse must be length 5.
So, the point (8, 3) is on the line AND it is 5 units from the point (4, 6)
Answer: C, E
Cheers,
Brent