13-3

Well as we all know this week we started chapter thirteen. Anyway section three of chapter thirteen is what I will be reviewing in this blog.
-To find the sum of the ____ terms of an arithmetic series:
Sn=n (t1 + tn)/1-r
-To find the sum of the ____ terms of a geometric series.
Sn= t1 (1-rn)/1-r
-A series is a list of numbers that are added together.
2+4+6+8
EXAMPLE TIME BOYS AND GIRLS
Find the sum of the first 8 terms of the arithmetic series.
11+14+17+20+…
First of all, set up the equation
S8= 8 (11 + )/2
To find tn, use your knowledge of the previous sections. T8= 11 + (n-1) (3)
T8= 11+3n-3 = 11 + 24-3= 25-3
T8=22
Plug this number into your equation next.
S8= 8 (11 + 22)/2= 132
That is about all there is to it. Do not forget your assignments that are due tomorrow! Have a fantastic week!

--SARAH (: