Question

Write a recursive rule for this sequence:
4, 6, 9, 13, 18...

Answer 1

looks like they increase by

2, 3, 4, 5,....

Answer 2

18 is the 5th term
18 = 13+5
hope that helps

Answer 3

@zzr0ck3r is 18 = 13+5 the recursive rule

Answer 4

not quite... but its a big hint

Answer 5

a recursive formula uses the previous term to get the new term... its normally has som operation associated with it

Answer 6

@campbell_st I am so confused

Answer 7

ok if we had
\[a_1 = 2\\and\\a_2=5
\]then we defined the recursive sequence to be
\[a_{n+1} = a_n+3\]
and we wanted to know what a_3 was then
\[a_3 = a_2+3\\a_3 = 5+3\]

Answer 8

now back to your problem
notice that
third term = the 2nd term + 3
fourth term = the third term + 4
fifth term = fourth term + 5
what does the sixth term =?

Answer 9

@sweetpink365 making more sense?

Answer 10

well if you come back
\[a_{n+1}=a_n+n\]
this is the answer. I don't like just giving answers but I want you to understand this. Please message me when you get back on so we can make sure you understand why.

Answer 11

well if you come back

\[let \space a_n = 4\\then\\a_n\space is\space given\space by\\a_{n+1}=a_n+n\]
this is the answer. I don't like just giving answers but I want you to understand this. Please message me when you get back on so we can make sure you understand why