Slope of a Line

The line below can be changed by dragging the blue points to a different location or by dragging the entire line.  Points C and D can be moved along the line, but they cannot change the line.

• Move C and D along the line and calculate the ratio
  m= ∆y/∆x=(y₂- y₁)/(x₂- x₁) for several different positions of the points. 
• Show the equation of the line and look for a relationship between the coefficients of the equation and  the slope and the y-intercept of the line.

Irina Boyadzhiev, Created with GeoGebra

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