Series and Finance (HSC SSCE Mathematics Advanced): Flashcards

Geometric progression (GP) theory

$A_n$ = (principal+interest) - (instalments+interest)

When amount owing reaches zero

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

One time period after taking out the loan

Set $A_n = 0$ and solve for $M$

Set $A_n = 0$ and solve for $n$ using logarithms

Must exceed initial interest charge

$A_{n+1} = A_n(1+R) - M$

$\log_a b = \frac{\log_c b}{\log_c a}$