Question

Find the sum of the first six terms of the geometric sequence with a1 = 2 and a2 = -4

Answer 1

Explanation:

Identify a1 and r for the sum of the geometric series.

−4, 8, −16, 32,…

a1 =

⇒ -4

r =

⇒ -2

Find the sum of the first six terms of the sequence.

S6 =

⇒ 84

Answer 2

I hope this helps you




a1=2



a2= -4



a3= -4-6= -10



a4= -10-6= -16



a5= -16-6= -22



a6= -22-6= -28