Khan Academy
Khan Academy: Symmetric Encryption
Check your understanding of symmetric encryption techniques, in this set of free practice questions designed for AP Computer Science Principles students.
Khan Academy
Khan Academy: Java Script Recap
Make sure you remember enough JavaScript before you keep going.
Texas Instruments
Texas Instruments: The Derivative as a Limit
Read about the near-simultaneous discovery of Calculus by Liebniz and Newton, then see some examples worked through of finding derivatives of functions using the limit definition of derivative. Following the examples are exercises with...