Mathematics
Gorzynski459
2016-09-29 17:17:06
Find the first four (4) terms of the sequence if An=(4) an-1 and a1 =1/2.
ANSWERS
Linaa321
2016-09-29 20:17:22

seems to be an=4(an-1) means the nth term is 4 times the previus term easy, times each term by 4 so 2nd is 4*1/2 or 2 3rd term is 2 times 4 or 8 4th term is 8*4=32 first 4 terms are 1/2, 2, 8, 32

narnie
2016-09-29 20:18:37

If the recursive formula is: a(n)=4*a(n-1) And a1=1/2 This is a geometric sequence because each term is a constant multiple of the previous term, this constant multiple is called the common ratio.  Any geometric sequence can be expressed as: a(n)=ar^(n-1), a(n)=nth term, a=initial term, r=common ratio, n=term number In this case, a=1/2 and r=4 so a(n)=(1/2)(4^(n-1)), so the first four terms are: 4^0/2, 4^1/2, 4^2/2, 4^3/2 1/2, 4/2, 16/2 64/2 1/2, 2, 8, 32

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