Nicala's Post

chapter 13 section 1

geometric and arithmetic sequences



arithmetic sequence is a sequence where the same number is added each time.

Formula: tn=t1+(n-1)d



geometric sequence is a sequence where the same number is multiplied each time.

Formula: tn=t1xr^n-1



Sample Problem



Find thed first four terms and state whether the sequences is arithmetic, geometric, or neither.

To find the first four terms, replace the n with 1.

Then 2, then 3, and 4.



tn=3n+2

tn=3(1)+2

tn=3+2

tn=5



tn=3n+2

tn=3(2)+2

tn=6+2

tn=8



tn=3n+2

tn=3(3)+2

tn=9+2

tn=11



tn=3n+2

tn=3(4)+2

tn=12+2

tn=14



Answer: 5,8,11,14

the sequence is arithmetic and d=3