Ch. 13-1

Sequences

arithmetic-add or subtract
geometric-multiply or divide
the variable "d" stands for the +/- term in arithmetic sequences
the variable "r" stands for the # of term in geometric sequences
ex: a. 4,8,12,16,... arithmetic (adding 4)
b. 9, 27/2, 81/4,...geometric (multiply by 3/2)
c. 4,7,11,16,22,...neither

Arithmetic: tn=t1+(n-1)d
Geometric: tn=t1*r^n-1
ex. find formula for n^m term :3,7,11,15
tn=t1+(n-1)d
tn=3+(n-1)(4)
tn=3+4n-4
tn=4n-1