Question

What is the recursive formula for this geometric sequence 2, -10, 50, -250

Answer 1

Answer:

$a_k=-5\cdot a_{k-1}, \,\,\,k=1,2,...\,\,\,\mbox{and}\,\,\,a_0=2$

Step-by-step explanation:

The recursion is as follows:

$a_k=-5\cdot a_{k-1}, \,\,\,k=1,2,...\,\,\,\mbox{and}\,\,\,a_0=2$

and unrolling the first few examples:

$a_0=2\\a_1=-5\cdot 2 = -10\\a_2= -5\cdot (-10) = 50\\a_3 = (-5) \cdot 50 = -250$

Answer 2

Answer: C

Step-by-step explanation: