Episode 2 — 2D & 3D Trigonometry

Cast Diagram

Learners will be able to:

• Identify the four quadrants of the Cartesian plane and their corresponding angle ranges. • Describe how angles are measured in an anti-clockwise direction on the Cartesian plane. • Explain the relationship between the values of x, y, and r in each quadrant. • Apply the CAST rule to determine the sign of trigonometric ratios in each quadrant. • Prove that cos theta is positive in the fourth quadrant using the ratio x over r.