Question

An arithmetic sequence "a" starts with 84, 77 define "a" recursively

Answer 1

Answer:

First, let's define an arithmetic sequence:

In an arithmetic sequence, the difference between any two consecutive terms is always the same.

Then we can write it in a general way as:

aₙ = a₁ + (n - 1)*d

where:

aₙ is the n-th term of the sequence.

d is the constant difference between two consecutive terms.

a₁ is the initial term of our sequence.

Now in this case we know that the first terms of our sequence are:

84, 77, ...

Then we know the initial term of our sequence:

a₁ = 84.

And the value of d can be calculated as:

d = a₂ - a₁ = 77 - 84 = -7

Then the general way of writing this sequence is:

aₙ = 84 + (n - 1)*(-7)

And the recursion relation is:

aₙ = aₙ₋₁ - 7

So for the n-th term, we must subtract 7 of the previous term.