2. Factorial Notation For any positive integer n, n! means: n (n – 1) (n – 2)... (3) (2) (1) 0! will be defined as equal to one. Examples: 4! = 43 2 1 = 24 The factorial symbol only affects the number it follows unless grouping symbols are used. 3 5! = 3 5 4 3 2 1 = 360 ( 3 5 )! = 15! = big number

3. Summation Notation is used to represent a sum. 1, 4, 9, 16,... Add the first six terms of the above sequence. 1 + 4 + 9 + 16 + 25 + 36 = 91 Summation Notation can be used to represent this sum. i is called the index of the summation 1 is the lower limit of the summation 6 is the upper limit of the summation is the sigma symbol and means add it up

4. The upper and lower limits can be any positive integer or zero. The index can be any variable

5. The number of terms in a summation is: upper limit – lower limit + 1 Practice #2: p. 934-935 19-41 odds

6. Find the first 6 terms of the sequence defined as: Fibonacci!

7. Using, notation, write a definition for the sequences below. CAN #6 Sequences/Sums on the Calculator Practice #3: p. 934 18-42 evens, 43-51 odds, 61-65 odds, 73