Question

2. Evaluate the geometric series given a = -120, r = 0.5 and n = 6

Answer 1

Explanation:

`S_(6)=-120(1-(0.5)^6)/(1-0.5)`

`=-120(1-((1)/(2))^6 )/(1-(1)/(2) ) \\=-120(1-(1)/(64) )/((1)/(2) ) \\=-240*(63)/(64) \\=-15*(63)/(4) \\=-(945)/(4)\\=-236.25`