Finite Geometric Series (Grade 12 NSC Matric Mathematics): Flashcards

Sum of specific number of terms from geometric sequence

Constant value that multiplies each term

$T_n = a \cdot r^{(n-1)}$

First term

Common ratio (constant multiplier)

$S_n = \frac{a(1 - r^n)}{1 - r}$

$S_n = \frac{a(r^n - 1)}{r - 1}$

$r \neq 1$

$n \times a$

Alternating positive and negative terms