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The recursive formula for 3, -15, 75, -375,...

User Qmega
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Answer:

Explanation:

This is an arithmetic sequence with a common difference of -12. To find the recursive formula, let's start by finding a general formula for the nth term.

Let a be the first term (3 in this case) and d be the common difference (-12 in this case). The nth term of the sequence can be found using the formula:

an = a + (n-1)d

Using this formula, the first four terms of the sequence are:

a1 = a + (1-1)d = 3 + (1-1)(-12) = 3

a2 = a + (2-1)d = 3 + (2-1)(-12) = 3 - 12 = -9

a3 = a + (3-1)d = 3 + (3-1)(-12) = 3 - 24 = -21

a4 = a + (4-1)d = 3 + (4-1)(-12) = 3 - 36 = -33

So, the sequence is: 3, -9, -21, -33, ...

We can now use this information to write the recursive formula for the sequence:

an = a(n-1) + d

So, for the sequence 3, -9, -21, -33, ... the recursive formula is:

an = an-1 + (-12)

This formula tells us how to find the nth term of the sequence given the (n-1)th term. The sequence starts with the first term a1 = 3 and the common difference is d = -12. By repeatedly applying the formula, we can find the values for the subsequent terms in the sequence.

User Morgane
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