1. Welcome to semester 2. Midterm Pass-back tomorrow
Welcome to semester 2! Midterm Pass-back tomorrow. Do Now: Create a Know-Want to know-Learned Chart about Functions and Cryptography

2. Vocabulary
Cryptography/cryptology-study of sending secure/secret messages.... Function-a rule that produces a specific result for a given input Domain-all possible input values for a function Range-all possible output values for a function

3. Some Examples of Cryptography…
Caesar cipher-Roman Empire 50 BC Morse code-1836 Enigma cipher-WWII (see right) Modern cryptography RSA-1972

4. Is it a Function? *A function only has 1 output for each input.
If the alphabet is the input and the symbols are the output, is it a function?
If the symbols are the input and the alphabet is the output, is it a function?

5. Domain and Range Examples
1) 𝑦=2𝑥 Domain: -∞<x< ∞ Range: -∞<y< ∞ 2) 𝑦=0𝑥 Domain: -∞<x< ∞ Range: y=0 3) 𝑦= 𝑥 Domain: -∞<x< ∞ Range: ? 4) 𝑦= 𝑥 2 Domain: -∞<x< ∞ Range: ? 5) 𝑦= 1 𝑥 Domain:? Range:?