Express the series using sigma notation. 1 + 4 + 16 + ... + 256. a.

c.

b.

d.

Please select the best answer from the choices provided

A
B
C
D

D

Step-by-step explanation:

By looking at the terms, we can notice that each term is 4 times the previous term. This means the series is geometric and we can rule out options A and B because of this. We can find the first terms of both options C and D to get:

first term c: 4

first term d: 1

The first term of our series is one, so that must mean D is the answer.