Monday

December 22, 2014

December 22, 2014

Posted by **Anonymous** on Tuesday, September 20, 2011 at 8:16pm.

I tried doing this, and I got 1.16 or something :S How exactly do I do this? Please tell me what formula to use. I was using the Sn = a(rn-1)/r-1

- Calculus -
**MathMate**, Wednesday, September 21, 2011 at 8:20pmThe geometric series up to the nth term is generally represented by the formula:

S(n)=a + ar + ar^2 + ar^3 .... + ar^(n-1)

Therefore

S(1)=a=0.7

S(2)=a+ar=a(1+r)=0.7*(1+2)

Therefore r=2

The formula for calculating the first n terms is

S(n)=a(r^n-1)/(r-1)

for n=12,

=0.7*(2^12-1)/(2-1)

You calculator should tell you that S(12) is below 3000.

**Answer this Question**

**Related Questions**

Calculus - - Reiny - If S1 = 0.7 and S2 = 2.1 in geometric series, what would ...

Math - The first two terms in a geometric series is 12. The sum of the first ...

math - sorry for before it is my first time using this website and this is the ...

math studies - An arithmetic series has a first term of -4 and a common ...

Geometric series - The sum of the first five terms of a geometric series is 186 ...

CALC II - Determine the convergence of the following series using the nth-...

Calc II - Use the comparison or limit comparison test to decide if the following...

Math. - The first term of a geometric series is 4 and the sum of the first three...

algebra - Can someone please help me with this problem? Thanks! Evaluate the ...

calculus - Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3...