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For each positive integer \(\mathrm{n}\), the quantity \(\mathrm{s_n}\) is defined such that \(\mathrm{s_{n+2} = (s_n)^2 - s_{n+1}}\). In addition, \(\mathrm{s_2 = 1}\).
Select values for \(\mathrm{s_1}\) and \(\mathrm{s_4}\) that are jointly compatible with these conditions. Make only two selections, one in each column.
s 1
s 4
-12
-7
-3
-1
0
We have a recursive sequence where:
Let's create a visual showing how the sequence builds:
\(\mathrm{s_1 \rightarrow s_2 \rightarrow s_3 \rightarrow s_4}\)
\(\mathrm{? \quad 1 \quad ? \quad ?}\)
Using our recursive formula, let's express \(\mathrm{s_3}\) and \(\mathrm{s_4}\) in terms of \(\mathrm{s_1}\):
For \(\mathrm{s_3}\):
For \(\mathrm{s_4}\):
Key Insight: We need to find values from the answer choices where \(\mathrm{s_4 = 2 - (s_1)^2}\)
Let's check each possible value of \(\mathrm{s_1}\):
If \(\mathrm{s_1 = -12 \rightarrow s_4 = 2 - (-12)^2 = 2 - 144 = -142}\)
Is -142 in our choices? No, continue.
If \(\mathrm{s_1 = -7 \rightarrow s_4 = 2 - (-7)^2 = 2 - 49 = -47}\)
Is -47 in our choices? No, continue.
If \(\mathrm{s_1 = -3 \rightarrow s_4 = 2 - (-3)^2 = 2 - 9 = -7}\)
Is -7 in our choices? Yes! ✓
Stop here - we found our answer.
Let's verify our answer works:
These values satisfy the recursive relationship \(\mathrm{s_{n+2} = (s_n)^2 - s_{n+1}}\) with \(\mathrm{s_2 = 1}\).