Wed 8/27

Warmup

1. Find your seat on the seating chart

2. Evaluate (find the value):

   1. 3²
   2. ( - 3)²
   3. - 3²

   4. 2

      3

      ⋅

      3

      4

   5. 2

      3

      ÷

      3

      4

   6. 2 3

      3 4

   7. 2 (3 - 5)

3. Simplify

   1. x² x³
   2. x/3 + x/6
   3. - 3( - x)

Textbooks

• Go in alphabetical order
• Find your book (see spreadsheet)
• Write your name & mine (Dreyer) in bookplate immediately

Welcome

Expectations

Variables

• Variables can represent numbers that we don't know, like in the equation x + 3 = - 2
• Variables can represent all choices of numbers, like a b = b a
• Variables can represent your choice of a number, like the x in y = 3 x - 2

Expressions

• Expressions, like 7 x - 4, represent numbers
• Evaluating an expression means finding its value for a certain value of the input variable, so for x = 3 we evaluate 7 x - 4 as 7⋅3 - 4 = ?
• Remember PEMDAS/GEMDAS/whatever (order of operations)

Functions

• A function can be defined as a rule that gives some output for every input
• The rule that gives an output of x + 1 for every input x is a function. What is the output if x = - 2?
• We write f(x) = x + 1 to define the function and to name f as that function. In this case, evaluating f(x) is the same as evaluating x + 1

Classwork/homework