Return to book
Review this book
About the author
Introduction
1. Surds & Indices
- 1.1. Types of Numbers
- 1.2. Raising Powers
- 1.3. Index Notation
- 1.4. Multiplication Rule
- 1.5. Division Rule
- 1.6. Power-On-Power Rule
- 1.7. Factor Rule
- 1.8. Negative Powers
- 1.9. Zero Power
- 1.10. Roots
- 1.11. Surds
- 1.12. Multiplying Surds
- 1.13. Dividing Surds
- 1.14. Simplifying Surds
- 1.15. Rationalise Denominators
- 1.16. Difference of Two Squares
- 1.17. Fractional Indices
2. Coordinate Geometry
- 2.1. Cartesian Coordinates
- 2.2. Distances
- 2.3. Straight Lines
- 2.4. Line Segments
- 2.5. Midpoint
- 2.6. Gradient
- 2.7. x-Intercept
- 2.8. y-Intercept
- 2.9. Lines Have Equations
- 2.10. Finding Gradient & y-Intercept
- 2.11. Intersection of Two Lines
- 2.12. Perpendicular Lines
3. Velocity & Acceleration
- 3.1. Scalars & Vectors
- 3.2. Describing Motion
- 3.3. Displacement & Distance
- 3.4. Velocity & Speed
- 3.5. Area Under a Graph
- 3.6. Constant Velocity
- 3.7. Acceleration & Deceleration
- 3.8. Constant Acceleration
- 3.9. Splitting Scenario into Stages
4. Representation of Data
5. Location & Spread
6. Quadratics
7. Inequalities
8. Functions
9. Factorials
10. Probability
11. Perms & Combs
- 11.1. Counting
- 11.2. Adding Rule
  - 11.2.1. Adding Examples
  - 11.2.2. Adding Quiz
- 11.3. Multiplying Rule
- 11.4. Repeated Addition
- 11.5. Multi-step Processes
- 11.6. Avoid Duplicate Outcomes
- 11.7. Arrangements
- 11.8. Factorial Notation
- 11.9. Permutations
- 11.10. Permutations Examples
- 11.11. Combinations
- 11.12. Grouping
12. Newton's Laws of Motion
13. Differentiation
14. Trigonometry
- 14.1. Trig are Ratios
- 14.2. Unit Circle
- 14.3. Period & Amplitude
- 14.4. Sine Curve
- 14.5. Cosine Curve
- 14.6. Tangent Curve
- 14.7. Common Values
- 14.8. Periodic Properties
- 14.9. Translation Properties
- 14.10. Solving Trig
- 14.11. Identities
15. Radians
- 15.1. Using Radians
- 15.2. Common Angles
- 15.3. Arc Length
- 15.4. Sector Area
- 15.5. Segment Area
- 15.6. Trig Graphs
- 15.7. Trig Symmetry
- 15.8. Inverse Trig
- 15.9. Solving Trig
16. Friction
- 16.1. What's Happening?
- 16.2. Coefficient of Friction
17. Arithmetic Series
- 17.1. Sequences
- 17.2. Describing Sequences
- 17.3. Inductive Definition
- 17.4. Triangle Numbers
- 17.5. Arithmetic Progressions
- 17.6. Summing APs
18. Binomial Theorem
- 18.1. The Long Way
- 18.2. Binomial Expansion
- 18.3. Finding the Coefficients
19. Geometric Series
- 19.1. Geometric Sequece
- 19.2. Summing GPs
- 19.3. Converging
- 19.4. Diverging
- 19.5. Oscillating
- 19.6. Exponential Growth & decay
20. Vectors
- 20.1. As Magnitude & Direction
- 20.2. Vectors as Arrows
- 20.3. Vectors aren't Arrows
- 20.4. Writing Vectors
- 20.5. Column Vectors
- 20.6. Position Vectors
- 20.7. Translation Vectors
- 20.8. Magnitude of Vector
- 20.9. Components from Angle
- 20.10. Adding Vectors
- 20.11. Subtracting Vectors
- 20.12. Vector Components
- 20.13. Scalars
- 20.14. Multiplying by Scalars
- 20.15. Unit Vectors
21. Vectors in 3D
- 21.1. Three Components
- 21.2. Base Vectors
- 21.3. Adding, Subtracting, Multiplying
- 21.4. No More Gradients
- 21.5. Skew Lines
- 21.6. Planes
- 21.7. Collinear Points
- 21.8. Magnitude
- 21.9. Multiplying Magnitude
- 21.10. Scalar Products
- 21.11. Unit Vectors
- 21.12. Finding Angles
- 21.13. Projections
22. Appendix – Useful Stuff
- 22.1. Sets
- 22.2. Geometry Terms

A Student Guide to A-Level Mathematics

Chapter 15
Radians

Radian is a way to measure angles.

Before, you would write angles in degrees…

Common angles in degrees: 90°, 180°, and 60°

Now, you can also write angles in radians… Common angles in degrees: 90°, 180°, and 60°

Don’t get it? Don’t worry, we’ll go through it step by step.

A Student Guide to A-Level Mathematics

Chapter 15Radians

Chapter 15
Radians