Question

4. Evaluate the geometric series given a1 = 4, r = -2 and n = 12

Answer 1

we know that

a1=7

r=2

n=14

then

Sn=a1*[(r^n)-1]/(r-1)-------------->S14= 7*[(2^14)-1]/(2-1)=114681

the answer is 114681