Flat or Vertical Through
Part of the Graphs & Systems section of Coddy's Algebra journey. Lesson 25 of 64.
Through one given point there is exactly one flat line and one vertical line, and both write themselves without a formula. Through (2, 5): the flat line keeps the height, y = 5; the vertical line keeps the column, x = 2.
The flat and the vertical line through (2, 5)
Point-slope covers the flat case too, with m = 0: y - 5 = 0(x - 2) collapses to y = 5. The vertical case it cannot touch, because a vertical line has no slope to plug in; its equation must be written directly.
Challenge
Draw the flat line through the point (4, -3).
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Graphs & Systems
1The Coordinate Plane
Two Numbers, One PointThe Four QuadrantsPoints on the AxesMirror PointsRecap: The Plane4Slope-Intercept Form
y = mx + bThe Starting HeightWrite the EquationSolve for yDraw From Any FormRecap: y = mx + b7Parallel & Perpendicular
Same Slope, Never MeetThe Perpendicular SlopeA Right-Angle LineRecap: Two Relations2From Rule to Line
A Rule Makes PointsThe Points Line UpOn the Line or Not?Between the DotsRecap: Rule to Line5Point-Slope Form
A Point and a SlopeFrom Two PointsFlat or Vertical ThroughDraw From a PointRecap: Point-Slope