thirteen.two

This week is our last week before exams :D I don't know about you, but that's good news to me :) two weeks ago we finished chapter thirteen excluding section seven. this past week we have been reviewing for exams and Friday we took our 13 test: hopefully I did well :D
Anyways, one of the sections tht I didn't find too tricky was section thirteen two.
section thirteen two is on Recursive Definitions. Recursive Definitions are sequences that are defined by what came before.
ex. t(n-1) means the number before. t(n-2) means two numbers before and so on.

example: 6,11,16,21..
we know that 5 is being added consistently each time.Therefore, the sequence is an arithmetic one. the formula is
tn=t(n-1) + 5 .

ex. find t3 if t1=5 t2=10 and t(n)= 2t(n-1) + t(n-2)
2(10)+5 = 25
t3 is 25.

simple enough :)