precalculus
posted by Anonymous
how do you find the 12th term of the sequence an= an1+3 ( the n and n1 are subscript) n>2 (also equal to)? I understand how to find the first six terms,but how do you use that to find the 12th . Thanks

Reiny
a_{n} = a_{n1} + 3
where a_{1} has to be known, I conclude that a_{1} = 2
I don't understand why n>2, I was expecting n>1
Ok, lets assume our terms are 2, 5, 8 ..... , each term is 3 more than the previous one
You could just grind it out and find the 12th terms , there are not too many for that.
However, I can translate this one to
a_{n} = 3n  1 , that will produce our sequence 2, 5, ...
so a_{12} = 3(12)  1 = 35
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