IGCSE Maths: Trigonometry

Overview

Trigonometry is one of the highest-weighted topics in IGCSE Mathematics, appearing in both Core and Extended papers. Core students need to master basic ratios and bearings, while Extended students tackle the sine rule, cosine rule, and 3D applications.

Core Syllabus Topics

• Basic trigonometric ratios (SOH-CAH-TOA)
• Right-angled triangle problems
• Bearings and navigation
• Angles of elevation and depression

Extended Syllabus Topics

• Sine rule
• Cosine rule
• Area of triangle using ½ab sin C
• 3D trigonometry
• Trigonometric graphs
• Solving trigonometric equations

Common Mistakes to Avoid

• Confusing when to use sine vs cosine rule
• Incorrect bearing notation (always measured clockwise from North)
• Forgetting to check for ambiguous case in sine rule
• Wrong calculator mode (degrees vs radians)