4 Multiple Choice 2 points Which is a geometric sequence? \( -5,2,9,16, \ldots \) \( 1,3,5,7, \ldots \) \( 1,4,9,16, \ldots \) \( -1,-2,-4,-8, \ldots \)

A geometric sequence is a sequence of numbers where each term after the first is found by multiplying the previous term by a fixed, non-zero number called the common ratio. In the case of the sequence \(-1, -2, -4, -8, \ldots\), each term is obtained by multiplying the previous term by 2, making it a classic example of a geometric sequence. To spot common mistakes, keep an eye out for sequences that appear to follow a pattern. Many students misidentify arithmetic sequences (where you just add a constant) as geometric ones. Always remember to check the multiplicative relationships between terms rather than simply the differences!