13-3

We just took a test on the whole chapter 13. This chapter was challenging and pretty complex. The chapter I had easy with was chapter 13. Chapter 13 section 13-3 is dealing with arithmetic series and the sum of the 1st n term of it. The formula for this is sn=n(t1+tn)/2

The sum of the 1st n terms of a geometric series is sn=t1(1-r^n)/1-r

Series- a list of numbers being added together

Finite – is a certain number

Infinite-unlimited number of terms


Example one arithmetic and one geometric problem:

Find the sum of the 1st 25 terms of the arithmetic series.
11+14+17+20+

tn=11+(25-1)3=83

s25=25(11+83)/2=1175 is your answer


Find the sum of the 1st 10 terms of the geometric series of 2-6+18-54+

-3

S10=2(1-3)^10/1-3=-29,524 is your answer



If you know your formulas and rules and everything .Section 13-3 is really easy and not hard and you should breeze by it easy. Know your definitions and formulas and everything and u will be good.