Arithmetic and Geometric Sequences!

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I hope you all had a wonderful weekend!

-Arithmetic mean of numbers of a&b is a+b/2
-Geometric mean of numbers a&b is the square root of ab
-Sequence: a list of numbers

-Arithmetic Sequence:
A sequence that is generated by adding the same number each time.
-Formula: tn=t1+(n-1)d
t1=1st term
n=term number
d=difference(what is being added)
tn=___ term

-Geometric Sequence:
A sequence that is generated by multiplying the same number each time. (To divide we use fractions)
-Formula: tn=t1(r)^(n-1)
t1=1st term
r=what is being multiplied
n=term number
tn=___ term

Example 1:
Find the first four terms of the sequence and state whether the sequence is arithmetic, geometric, or neither.
tn=2n+3
n=1 2(1)+3=5
n=2 2(2)+3=7
n=3 2(3)+3=9
n=4 2(4)+3=11
arithmetic, because you are adding 2 each time

Example 2:
Find a formula for tn.
1, 4, 7, 10, ...
arithmetic, because you are adding 3 each time
d=3
t1=1
n=n
tn=t1+(n-1)d
1+(n-1)3
=1+3n-3
=3n-4