Test a Point
Part of the Graphs & Systems section of Coddy's Algebra journey. Lesson 44 of 64.
When the side is not obvious, ask a point. For y < 2x + 3 test the origin: is 0 < 2(0) + 3? Yes, 0 < 3, so the origin sits in the shaded region, and the shading goes on the origin side of the boundary.
Any point off the boundary works, but (0, 0) is the favourite because substituting zeros is instant. If the test point satisfies the inequality, shade its side; if not, shade the other one.
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