sequences

Question 1

increasing or decreasing

Answer 1

• when sequence has Un in it, that is when you plug in previous terms. This is called recurrence relation. You can be asked to describe a sequence in terms of recurrence relation
• when sequence has just n plug in 1 then 2 then 3 then 4 etc……
  this can be used to find out if sequence is increasing, decreasing or periodic

Question 2

periodic sequences

Answer 2

• has period (or order) k, where k is the smallest number of terms that repeat as a block of numbers.

Question 3

converging sequences

Answer 3

• a sequence U1, U2, U3….. converges to a number L if the terms get ever closer to L.
  L is called the limit of the sequence
• Un –> L as n–> ∞

Question 4

nth term of an arithmetic sequence

Answer 4

Un = a + (n-1)d

Question 5

arithmetic series

Answer 5

The addition of terms in an arithmetic sequence
- can have finite series
- or infinite series