Question

What is the sum of the geometric series?

Sigma-Summation Underscript n = 1 Overscript 4 EndScripts (negative 2) (negative 3) Superscript n minus 1
–122
–2
40
54

Answer 1

Explanation:

Σ^n=1 -144 (1/2)n-1

This is a finite geometric series with n

=4, a₁-144, and r = 2.

S = a₁ (1-r") / (1 − r)

S-144 (1 - (1/2)) / (1 - 1/2)

S=-270

If you wanted to find the infinite sum (n

= ∞0)

:S = a₁ / (1 − r)

S-144/(1-1/2)

S=-288