← GSEB Class 11
Trigonometric Functions
Chapter Overview
Trigonometric functions (sin, cos, tan, cosec, sec, cot) are defined using the unit circle and right triangles. Angles are measured in degrees and radians. The chapter covers signs in quadrants, identities including Pythagorean and sum/difference formulas, double and half-angle formulas. GSEB emphasizes applications in surveying and construction relevant to Gujarat's infrastructure.
Graphs of trigonometric functions show periodic nature. Trigonometric equations use general and principal solutions. Applications include heights and distances using sine and cosine rules.
Topics Covered
- Degree and Radian Measure
- Unit Circle Definitions
- Quadrant Signs
- Trigonometric Identities
- Sum and Difference Formulas
- Double and Half-Angle Formulas
- Trigonometric Equations
- Graphs of Trig Functions
- Sine and Cosine Rules
Key Formulas
pi radians = 180 degrees
sin2(A) + cos2(A) = 1
sin(A + B) = sin A cos B + cos A sin B
cos(A + B) = cos A cos B - sin A sin B
sin 2A = 2 sin A cos A
cos 2A = cos2 A - sin2 A
Real-World Applications
Applications: Navigation, astronomy, engineering, physics (wave analysis), computer graphics, and architecture.
Study Tips
Tip: Memorize the unit circle values
Tip: Practice deriving identities from basic formulas
Tip: Solve GSEB previous year questions for pattern familiarity