Agenda.

Lecture on Coordinates (30 minutes).

How are they treated in schoolbooks?

• A page from the Singapore 6th grade text
• Pages from Glencoe Algebra I (2006 Louisiana Edition).
  • 1.9. Graphing Data on the Coordinate Plane
  • 6.1. Rate of Change and Slope
  • 6.2. Slope-Intercept Form

Coordinates from an advanced perspective.

• Coordiante systems on a line. Naked lines. Imposing a coordiante system. Coordiantes are functions. Relationships between coordiate systems.
• Coordinate systems on the plane. Naked planes. Systems with perpendicular axesand other systems. Changing coordinates.

Coordinates from an historical perspective.

• Coordinates in Descartes' Geometry. Device on p. 318. Device on p. 320.
• Coordinates in Newton's work

Student discussion. (25 minutes).

Student groups will prepare answers to the question, "Why the graph of a linear equation is a line?" We will compare proposals.

Work on homework. (25 minutes).

Homework

• Hand in Wednesday March 9: Problem sets 3.2 and 3.3.