SOLUTION: How to write a formula for the nth term of each geometric sequence below? Then use the formula to find a8, the eight term of the sequence.
(a) 4, -4, 4, -4,.....
(b) 16, 8, 4,...
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-> SOLUTION: How to write a formula for the nth term of each geometric sequence below? Then use the formula to find a8, the eight term of the sequence.
(a) 4, -4, 4, -4,.....
(b) 16, 8, 4,...
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Question 1119500: How to write a formula for the nth term of each geometric sequence below? Then use the formula to find a8, the eight term of the sequence.
(a) 4, -4, 4, -4,.....
(b) 16, 8, 4,..... Answer by htmentor(1343) (Show Source):
You can put this solution on YOUR website! The general form for the nth term of a geometric sequence is a_n = ar^(n-1)
where a = the 1st term and r is the common ratio
(a) In this case, r =-4/4 = -1, and a = 4
Thus a_n = 4(-1)^(n-1)
(b) In this case, r = 8/16 = 1/2, a = 16
Thus a_n = 16(1/2)^(n-1)
