The sum of a geometric sequence is a(1-rn)/(1-r)
In this case, a = 8, r = -2 and n=15
So the sum is 8(1-(-2)15)/(1+2)
=8(1+32768)/3
=87,384
So the sum of the first 15 terms of the sequence 8, -16, 32, -64.... is 87,384.
Yes, that's what a geometric sequence is about.
yes
A geometric sequence with 5 terms can alternate by having positive and negative terms. For example, one such sequence could be (2, -6, 18, -54, 162). Here, the first term is (2) and the common ratio is (-3), leading to alternating signs while maintaining the geometric property.
The terms are: 4, 8 and 16
un = u0*rn for n = 1,2,3, ... where r is the constant multiple.
Yes, that's what a geometric sequence is about.
A descending geometric sequence is a sequence in which the ratio between successive terms is a positive constant which is less than 1.
yes
A static sequence: for example a geometric sequence with common ratio = 1.
FALSE (Apex)
Ratio
It is 4374
The difference between succeeding terms in a sequence is called the common difference in an arithmetic sequence, and the common ratio in a geometric sequence.
The terms are: 4, 8 and 16
The sequence 2, 3, 5, 8, 12 is neither arithmetic nor geometric. In an arithmetic sequence, the difference between consecutive terms is constant, while in a geometric sequence, the ratio between consecutive terms is constant. In this sequence, there is no constant difference or ratio between consecutive terms, so it does not fit the criteria for either type of sequence.
un = u0*rn for n = 1,2,3, ... where r is the constant multiple.
No. Although the ratios of the terms in the Fibonacci sequence do approach a constant, phi, in order for the Fibonacci sequence to be a geometric sequence the ratio of ALL of the terms has to be a constant, not just approaching one. A simple counterexample to show that this is not true is to notice that 1/1 is not equal to 2/1, nor is 3/2, 5/3, 8/5...