Question 258595: Find all points on the y-axis that are 5 units from the point (4,4).
The midpoint of the line segment from P1 to P2 is (5,-4). if P2 is (7,-2), what is P1?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Find all points on the y-axis that are 5 units from the point (4,4).
Points on the y-axis have the form (0,y)
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Solve the distance equation:
5 = sqrt[(4-0)^2 + (4-y)^2]
25 = 16 + 16 - 8y + y^2
y^2 - 8y + 7 = 0
(y-7)(y-1) = 0
y = 7 or y = 1
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Points: (0,7) and (0,1)
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The midpoint of the line segment from P1 to P2 is (5,-4). if P2 is (7,-2), what is P1?
Let P1 be (x,y)
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Note: The coordinates of the midpoint are the average of the corresponding
endpoint coordinates.
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(x+7)/2 = 5
x+7 = 10
x = 3
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(y-2)/2 = -4
y-2 = -8
y = -6
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P1 is (3,-6)
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Cheers,
Stan H.
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