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Points in the coordinate system

Two points in a coordinate system: how far apart are they, where is the middle, and which line goes through both?

Your numbers

Answer

Distance between the points

10

Midpoint

(1 ; 4)

The line through the points

y = 0.75x + 3.25

xy-10-10-5-5551010ABM

How to work it out

  1. 1Δx = 5 − -3 = 8 · Δy = 7 − 1 = 6
  2. 2|AB| = √(Δx² + Δy²) = √(64 + 36) = 10
  3. 3M = ((-3 + 5) / 2 ; (1 + 7) / 2) = (1 ; 4)
  4. 4a = Δy / Δx = 6 / 8 = 0.75 · b = y₁ − a·x₁ = 3.25

The formula

|AB| = √((x₂ − x₁)² + (y₂ − y₁)²)

The distance formula is Pythagoras: Δx and Δy are the legs.

M = ((x₁ + x₂)/2 ; (y₁ + y₂)/2)

The midpoint is the average of the coordinates.

More: Geometry

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