Final answer:
The formula for a sequence starting with a first term of 4 and a common ratio of -2 is An = 4 * (-2)^(n - 1).
Step-by-step explanation:
The first term (also known as the initial term) in a sequence and the common ratio are essential components in the formula for a geometric sequence. Given that the first term is 4 and the common ratio is -2, the formula for the nth term of the sequence (An) can be derived using the general formula for a geometric sequence, which is An = A1 * r^(n - 1), where A1 is the first term, r is the common ratio, and n is the term number.
To find the formula for this specific sequence, A1 would be 4, and r would be -2. Thus, the formula becomes An = 4 * (-2)^(n - 1). So, the answer that correctly represents the formula for this sequence is 4. An = 4 * (-2)^(n - 1).