What is the equation for a geometric sequence with a first term of 2 and a second term of - 8?

an = 2 (8) n - 1

an = 2 (-8) n - 1

an = 2 (4) n - 1

an = 2 (-4) n - 1

an = 2 (-4) ^ (n - 1)

Step-by-step explanation:

A geomteric sequence is in the form

an = a1 (r) ^ (n-1)

a1 = 2 and

a2 = - 8

-8 = 2 r ^ (2-1)

Divide each side by 2

-4 = r ^1

r = - 4

an = 2 (-4) ^ (n-1)