2006-07-06 16:11:44 · 8 answers · asked by sneaky comet 3 in Science & Mathematics ➔ Mathematics
S=a(1-r^n)/(1-r)
S is the sum, a is the first element, r is the ratio, n is the number of elements
2006-07-06 16:17:13 · answer #1 · answered by MsMath 7 · 3⤊ 4⤋
Surely anyone know the formula for finding the sum of a finite geometric series. So do I and I am one of the anyone.
a+ar+ar2+...+ar^(n-1) = a{(r^n - 1)/(r - 1)}
2006-07-07 01:44:58 · answer #2 · answered by Thermo 6 · 0⤊ 1⤋
If a is the first number in the n-term series, and r is the common ratio, i.e. the series goes a + a*r +a*r^2 +...+a*r^(n-1):
Sum=a*(r^n-1)/(r-1) if r >1
Sum=a*(1-r^n)/(1-r) if r <1
2006-07-07 01:18:19 · answer #3 · answered by torturapatente 1 · 1⤊ 0⤋
1 + r + r^2 + r^3 + ... + r^(n-1) = ( 1 - r^n ) / ( 1 - r )
2006-07-06 23:16:17 · answer #4 · answered by AnyMouse 3 · 0⤊ 1⤋
Capital Sigma
2006-07-06 23:14:31 · answer #5 · answered by Poncho Rio 4 · 0⤊ 1⤋
s=a1/(1-r), a1=first number in series, r= ratio
2006-07-06 23:35:46 · answer #6 · answered by the truth 1 · 0⤊ 1⤋
S(infinitity) = (a1)/(1 - r)
2006-07-07 01:30:53 · answer #7 · answered by Sherman81 6 · 0⤊ 1⤋
http://en.wikipedia.org/wiki/Geometric_series#Geometric_series
2006-07-07 01:11:33 · answer #8 · answered by 99 ks 2 · 0⤊ 1⤋