Final answer:
Using the given recursive formula and initial conditions, the first four terms of the sequence are calculated to be 8, -3, 2, and 1.
Step-by-step explanation:
To find the first four terms of the sequence defined by the recursive formula an = 2an-1 + an-2, we'll use the given initial conditions a1 = 8 and a2 = -3. To find the next term, a3, we apply the formula using n=3:
- a3 = 2a2 + a1
- a3 = 2(-3) + 8
- a3 = -6 + 8
- a3 = 2
Now, for the fourth term, a4, we again apply the formula:
- a4 = 2a3 + a2
- a4 = 2(2) - 3
- a4 = 4 - 3
- a4 = 1
Therefore, the first four terms of the sequence are 8, -3, 2, and 1.