A Right-Angle Line

Part of the Graphs & Systems section of Coddy's Algebra journey. Lesson 35 of 64.

Drawing a perpendicular through a given point is the point-and-slope drawing again, with the slope computed first. Perpendicular to y = 1/2x + 1 means slope -2; through (0, -1) that is the line y = -2x - 1.

The two lines cross once, at a right angle, and every step of one against the other confirms the trade: a gentle 1/2 climb against a steep -2 fall.

Challenge

The line y = 1/2x - 1 is drawn. Draw the line perpendicular to it through (0, 3).

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This 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 Point The Four Quadrants Points on the Axes Mirror Points Recap: The Plane

4Slope-Intercept Form

y = mx + b The Starting Height Write the Equation Solve for y Draw From Any Form Recap: y = mx + b

7Parallel & Perpendicular

Same Slope, Never Meet The Perpendicular SlopeA Right-Angle LineRecap: Two Relations

10Systems by Graphing

Two Lines, One Answer Solve by Drawing Check the Crossing When Lines Never Cross Recap: By Graphing

2From Rule to Line

A Rule Makes Points The Points Line Up On the Line or Not?Between the Dots Recap: Rule to Line

5Point-Slope Form

A Point and a Slope From Two Points Flat or Vertical Through Draw From a Point Recap: Point-Slope

8Function Notation

The Name of a Rule Inputs With Signs Find the Input The Graph of f Recap: f(x)

11Solving Systems Exactly

Substitution Isolate First Elimination Scale, Then Add Three Unknowns Two Numbers, Two Facts Recap: Two Methods