Find the sum of the first 5 terms of the geometric sequence 1,-4,16, ...
A) -205
B) -341
C) 341
D) 205

Question

Find the sum of the first 5 terms of the geometric sequence  1,-4,16, ...
A)  -205 
B)  -341 
C) 341
D) 205

Quizplus · Accepted Answer

The common ratio (r) of the sequence is -4 (each term is -4 times the previous one). The sum of the first n terms of a geometric sequence is given by S_n = a(1 - r^n) / (1 - r), where a is the first term and r is the common ratio. Plugging in the values: S_5 = 1(1 - (-4)^5) / (1 - (-4)) = 1(1 + 1024) / 5 = 1025 / 5 = 205.

Find the Sum of the First 5 Terms of the Geometric