Final answer:
Using the recursive formula, we find a2 to be -2, then compute a3 as 1, and finally determine a4 to be -2.
Step-by-step explanation:
We start by finding the value of a2 using the given recursive formula, where a1=1. So,
a2 = (a1)^2 - 3 = (1)^2 - 3 = 1 - 3 = -2.
Next, we find a3:
a3 = (a2)^2 - 3 = (-2)^2 - 3 = 4 - 3 = 1.
Finally, we calculate a4:
a4 = (a3)^2 - 3 = (1)^2 - 3 = 1 - 3 = -2.
Therefore, the value of a4 is -2.