Difference Equations to Differential Equations: An introduction to calculus by Dan Sloughter is available in pdf format for free. Thorough, relatively concise calculus text. Includes many examples, graphs, and problems.

**Contents**

- Sequences, limits, and difference equations
- Functions and their properties
- Best affine approximations
- Integration
- Polynomial approximations and Taylor series
- More transcendental functions
- The complex plane
- Differential equations

**Book Details**