Warm Up 1) Solve: -2(x + 9) + 13 = -11 2) A triangle has side lengths of 5, 15, and 14. Is the triangle a right triangle? Why or Why not?

HW Check 3.6

Page 5 of the Unit 3 packet

You have studied many relationships between quantities. In this lesson you will learn about a special type of relationship called a function. In this lesson you will: use a coding grid to write a coded message create and use a letter-shift code determine whether given relationships are functions

Function Relation – set of ordered pairs (input and output values) Function – a relationship between a set of inputs and outputs **For any input, the function will have exactly one output. Domain – the set of all x values (input values) in a relation Range – the set of all y values (output values) in a relation

The study of secret codes is called cryptography. In cryptography, encryption is the process of transforming information using an algorithm (called a cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information. The reverse process, i.e., to make the encrypted information readable again, is referred to as decryption (i.e., to make it unencrypted).

The history of cryptography began thousands of years ago. The earliest known use of cryptography is found in non-standard hieroglyphs carved into monuments from the Old Kingdom of Egypt circa 1900 BC. Until recent decades, it has been the story of what might be called classic cryptography — that is, of methods of encryption that use pen and paper, or perhaps simple mechanical aids.

In the early 20th century, the invention of complex mechanical and electromechanical machines, such as the Enigma rotor machine, provided more sophisticated and efficient means of encryption; and the subsequent introduction of electronics and computing has allowed elaborate schemes of still greater complexity, most of which are entirely unsuited to pen and paper.

Until the 1970s, secure cryptography was largely the preserve of governments. Two events have since brought it squarely into the public domain: the creation of a public encryption standard and the invention of public- key cryptography. Modern encryption protects our information – especially when dealing with money – ATMs, credit cards, etc.

Secret Codes Investigation – pages 2 & 3

Stand up/Sit Down For each of the following stand if the relation is a function, stay seated if it is not a function. Be ready to justify your choice!

1)

2)

3)

4)

Coming up… Homework tonight – 3.7 QUIZ tomorrow!! Midterm coming up next Wednesday. Start looking over Units 1 – 3 materials.