How do you find the first five terms of each sequence #a_1=12#, #a_(n+1)=a_n-3#?

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Answer 1 · 2016-10-18T17:55:32

The first 5 terms are #12, 9, 6, 3, 0#

#a_(n+1)=a_n-3# and #a_1=12#

Find the first five terms.

This is a recursively defined sequence, which means you use the previous term to find the next.

The first term is #a_1=12#.

The 2nd term is #a_2=a_(1+1)=a_1-3=12-3=9#

The 3rd term is #a_3=a_(2+1)=a_2-3=9-3=6#

Note that you are subtracting 3 to find the next term.

So, #a_4=3# and #a_5=0#.

The first 5 terms are #12, 9, 6, 3, 0#.