Flashcard 15 - 11th Grade Mathematics: Algebra Flashcard Set for the SBAC

1023

While you can add the first 10 terms in the geometric series, you can also use this formula to find the sum:

\(S_n = a \cdot \dfrac{1-r^n}{1-r}\) where:

n is the number of terms in the sequence
r is the common ratio
a is the first term in the sequence of numbers you are adding.

So:

\[S_{10} = (1) \cdot \dfrac{1-2^{10}}{1-2} = \dfrac{-1023}{-1} = 1023\]