series (1 Viewer)

[CJS101]

hey can someone please remind of all the formula used in series, from arithmetic to compound interest
thanks

 

[dir3]

Arithmetic:

nth term : Tn = a+(n-1)d
n = term number
a = first term
d = common difference

sum : Sn = n/2[2a+(n-1)d]
n = term number
a = first term
d= common difference

or : Sn = n/2(a+l)
n= term number
a = first term
l = last term

Geometric:

nth term: Tn= ar^n-1
n = term number
a = first term
r = common ratio

sum:
if > 1 : Sn = a(r^n -1)/r - 1
if <1 : Sn = a(1-r^n)/1-r

a = first term
r = common ratio
n = term number

Limiting Sum:

S(infinity) = a/1-r

a= first term
r = common ratio





hope those help

 

[CJS101]

thanks dir3, much needed
does anyone have like super,loan repayment and that

 

[RiSeAgAiNSt2538]

unless u do standard maths u shouldnt use the formula for time payments as in the HSC some questions make you derive the formula so that is the way to go.

 

[munchiecrunchie]

unless u do standard maths u shouldnt use the formula for time payments as in the HSC some questions make you derive the formula so that is the way to go.

Really? I just memorise it and apply it where I can.

The formula is:

A = p(1 + r)^n

Where
A is the amount
p is the initial amount invested
r is interest rate (in decimal form)
n is the number of time periods