SOLUTION: Find all points having an x -coordinate of 2 whose distance from the point (-2,-1) is 5? I think it uses distance formula or a midpoint formula.

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Question 13249: Find all points having an x -coordinate of 2 whose distance from the point (-2,-1) is 5? I think it uses distance formula or a midpoint formula.
Found 2 solutions by akmb1215, rapaljer:
Answer by akmb1215(68) About Me  (Show Source):
You can put this solution on YOUR website!
You're right - you use the distance formula for this. D+=+sqrt%28%28x2+-+x1%29%5E2+%2B+%28y2+-+y1%29%5E2%29. You know one point, the x-coordinate of the other point, and the distance between the two points. When you plug this information into the equation, you get 5+=+sqrt%28%282+-+2%29%5E2+%2B+%28y2+-+-1%29%5E2%29. To get rid of the square root, sqare both sides to get 25+=+%282-2%29%5E2+%2B+%28y2+-+-1%29%5E2. Work out the subtraction in the parentheses and then square the answers to get: 25+=+y2%5E2+%2B+2y2+%2B+1. Move the 25 over to get y2%5E2+%2B+2y2+-+24+=+0. Factor this out to get %28y2+%2B+6%29+%28y2+-+4%29+=+0. Your two points are (2,-6) and (2,4).

Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
The points you need to find are (2, y) such that the distance from (2,y) to (-2, -1) is 5. You are right to use the distance formula!!
+sqrt%28+%282-%28-2%29%29%5E2+%2B+%28y-%28-1%29%29%5E2%29+=+5
Square both sides of the equation:
+%284%29%5E2+%2B+%28y%2B1%29%5E2+=+25+
+16+%2B+%28y%2B1%29%5E2+=+25+
+%28y%2B1%29%5E2+=+9
+y%2B1+=+3 or y%2B1=-3
y=3-1; or y = -3 -1
y = 2 or y = -4

The points are (2,2) and (2, -4).

Check: Distance from (2,2) to (-2, -1) = sqrt+%284%5E2+%2B+3%5E2%29+=+5
Distance from (2,-4) to (-2, -1) = sqrt+%284%5E2+%2B+3%5E2%29+=+5

R^2 at SCC