Question

If a1 = and an=an-1-4 then find the value of a4

Answer 1

To find the value of a4, we need to use the recursive formula for the sequence. The formula gives us the nth term in the sequence in terms of the (n-1)th term.

We are given that a1 = -7, so we can use the recursive formula to find a2, a3, and a4:

a2 = a1 - 4 = -7 - 4 = -11

a3 = a2 - 4 = -11 - 4 = -15

a4 = a3 - 4 = -15 - 4 = -19

Therefore, the value of a4 is -19.