2. Write a function of the geometric sequence with a starting term of 10 and a common ratio of 4. Find the fourth term.

f(n) = 10 · 44-1, the fourth term is 640
f(n) = 2 . 10^-1, the fourth term is 1, 024
f(n) = 4.10^-1, the fourth term is 64 DI
f(n) = – 10. – 4n-1, the fourth is -128 ​