Applications of APs and GPs (HSC SSCE Mathematics Advanced): Quizzes

Sequence is ordered list; series is sum

$T_n = a + (n-1)d$

$x = \frac{a + b}{2}$

$x^2 = ab$

$S_n = \frac{1}{2}n(a + \ell)$

$-1 < r < 1$

$S_{\infty} = \frac{a}{1 - r}$

$r = 0.94$

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

Neither $r$ nor any term can be zero