SOLUTION: Ex. 9. Plot the points(0,-10), (8,1), (15,10). How far is the second point from the line joining the other two? Solve Ex. 9 for the points (-10,-20), (17,0), (30, 10). Please

Algebra ->  Length-and-distance -> SOLUTION: Ex. 9. Plot the points(0,-10), (8,1), (15,10). How far is the second point from the line joining the other two? Solve Ex. 9 for the points (-10,-20), (17,0), (30, 10). Please      Log On


   



Question 1021162: Ex. 9. Plot the points(0,-10), (8,1), (15,10). How far is the second point from the line joining the other two?
Solve Ex. 9 for the points (-10,-20), (17,0), (30, 10).
Please solve.

Found 2 solutions by Cromlix, robertb:
Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Hi there,
Second point (8,1)
Line between (0,-10) and (15,10)
Find mid point of line
Formula:
x1 + x2/2, y1 + y2/2
0 + 15/2, -10 + 10/2
(7.5,0)
Distance from (8,1) to (7.5,0)
Formula:
√(x2 - x1)^2 + (y2 - y1)^2
√(7.5 - 8)^2 + (0 - 1)^2
√(-0.5)^2 + (-1)^2
√0.25 + 1
√1.25
= 1.11 units
Ex 9.
Distance from (17,0)
to line between (-10,-20) and (30, 10)
Mid point of line:
-10 + 30/2, -20 + 10/2
20/2, -10/2
(10,-10)
Distance between (17,0) and (10,-10)
√ (10 - 17)^2 + (-10 - 0)^2
√(-7)^2 + (-10)^2
√ 49 + 100
√149
= 12.2 units.
Hope this helps :-)

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
The line connecting the points (0,-10) and (15,10) is 4x-3y-30 = 0 (in general form). (You should be able to determine this!)
From analytic geometry the distance of a point from a line not containing it is
d+=+abs%28ax%5B0%5D%2Bby%5B0%5D%2Bc%29%2Fsqrt%28a%5E2%2Bb%5E2%29, where (x%5B0%5D,y%5B0%5D) is the given point.
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