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Write an recursive formula for an, the nth term of the sequence 5, -1, -7,....

User SeeDoubleYou
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1 Answer

30 votes
30 votes

The terms of the sequence are 5, -1, -7

Let us find the common difference between each two consecutive terms

-1 - 5 = -6

-7 - (-1) = -7 + 1 = -6

Then the common difference is -6

The first term is 5

The recursive formula is


a_1=1stterm;a_n=a_(n-1)+d

Substitute in the formula the value of the 1st term and d the common difference


a_1=5;a_n=a_(n-1)+(-6)

Remember (+)(-) = (-)


a_1=5;a_n=a_(n-1)-6

This is the recursive formula for the sequence

User Catomatic
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