4 Trigonometric functions
4A The general tangent function
4B General trigonometric functions
4C Reciprocal trigonometric functions
4D Solving Trigonometric equations
4E Modelling using trigonometric functions
4F Trigonometric relationships
4G Double angle identities
4H Angle sum and difference identities
4I Trigonometric equations in quadratic form (Extension-not in outline)