hello
here's the question I need a hand with
Find the first three terms of a geometric progression where all terms are positive, S4 (the sum to four terms) = 21 2/3 and the sum to infinity = 27
thanks in advance, all help is much appreciated
hello
here's the question I need a hand with
Find the first three terms of a geometric progression where all terms are positive, S4 (the sum to four terms) = 21 2/3 and the sum to infinity = 27
thanks in advance, all help is much appreciated
Find the first three terms of a geometric progression where all terms are positive, S4 (the sum to four terms) = 21 2/3 and the sum to infinity = 27
The formulas used for GP
Sn=a(1-(r^n))/(1-r) for n terms...(2)
and for infinite terms
Si=a/(1-r) for 0<r<1.......(1)
a=1st term
r=constant ratio
use it in above
put (1) in (2) for n= 4 to get r and thus a
further use (2) to find the terms reqd
Hello, listeningintently!
You're expected to know these formulas:Find the first three terms of a geometric progression
where all terms are positive, , and
. . Sum of the first terms: .
. . Sum to infinity: .
The sum of the first four terms is .[1]
The sum to infinity is 27: . .[2]
Substitute [2] into [1]: .
. .
Substitute into [2]: .
Therefore, the first three terms are: .