Question

A recursive rule for an arithmetic sequence is a1 = -4; an = an - 1 + 11

Answer 1

Step-by-step explanation:

a1 is already defined : a1 = -4

since an = an-1 + 11, we know d (the constant being added from term to term) is 11.

d = 11

the basic iterative rule is also already defined :

an = an-1 + 11

but we can always also express this in terms of a1 :

an = a1 + 11×(n-1)

therefore,

a10 = -4 + 11×9 = -4 + 99 = 95