Trigonometry Help

Trig can feel like a big jump at first — suddenly there are new functions, new notation, and more triangles than you ever wanted to see. But it follows the same logic as everything else in math. Work through the lessons below and it will start to click.

Lessons

• Addition Formulas — sin(A+B), cos(A+B), and related formulas
• Derivatives of Trig Functions — how sine, cosine, and tangent behave under differentiation
• Double and Half Angle Formulas
• Trigonometric Identities — a full reference list including Pythagorean identities
• Basic Trigonometry — Khan Academy intro to sine, cosine, and tangent
• Magic Identity — the trig magic hexagon: a visual way to remember the identities
• Measuring Angles in Radians — why radians exist and how to use them
• Right Angle Trig — definitions from Clark University
• Trig Functions — a solid review of all six functions from Paul's Online Notes
• What is Trigonometry? — overview from Clark University

Featured Lesson

Review the double angle formulas — they show up constantly in calculus.