Question

A recursive rule for an arithmetic sequence is a1=-4 an=4+a (n-1) What is the 4th term?

Answer 1

Answer:

4th term is 8

Step-by-step explanation:

$\left\{\begin{array}{ccc}a_1=-4\\a_n=4+a_{n-1}\end{array}\right\\\\a_2=4+a_1\to a_2=4+(-4)=4-4=0\\\\a_3=4+a_2\to a_3=4+0=4\\\\a_4=4+a_3\to a_4=4+4=8$