The Starting Height
Part of the Graphs & Systems section of Coddy's Algebra journey. Lesson 18 of 64.
The y-intercept is where a graph meets the y-axis, and it always has x = 0. For a line in slope-intercept form it is simply (0, b); for anything else, set x to 0 and see what remains.
y = -2x + 3 starts at (0, 3)
In stories the intercept is the starting amount: the opening fee before any kilometres, the water level before the tap opens. The slope is the rate; the intercept is where things stand at zero.
Challenge
A line is drawn. Place the point where it crosses the y-axis.
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 Line