Download Lesson 4.3: Using Recursive Formulas

Lesson 4.3: Using Recursive
Formulas
Advanced Math Topics
Definition of Recursive Formula

The formula for a sequence that
tells you how to find the nth term
from the term(s) before it.
Example/Steps

Part 1: the value of the 1st term(s) are
given


Part 2: A recursion equation shows how
to find each term from the term before it.


a1 = 1
an=2an-1
Part 3: Plug numbers into the formula to
find the next terms in the sequence.



a2=2a2-1=2a1=2(1)=2
a3=2a3-1=2a2=2(2)=4
a4=2a4-1=2a3=2(4)=8
Examples


a1=12
an=3(an-1)
n
Examples



a1=3
a2=2
an=an-1-2an-2
Examples



a1=1
a2=2
an=(an-2)2-(an-1)2
Examples


a1=10
an= 1
an-1
Word Problem

Start January by plugging in 0 for
an-1 and then fill in chart
Homework


Page 225/ 8-13
Remember that i is an imaginary
number and i2 = -1