Question

Find the first four terms of the sequence defined below, where n represents the position of a term in the sequence. Start with n = 1.

an = –10n + 9

Answer 1

To find the first four terms of the sequence defined by the formula \( a_n = -10n + 9 \), we will calculate the values of \( a_n \) for \( n = 1, 2, 3, \) and \( 4 \).

1. For \( n = 1 \):
\[
a_1 = -10(1) + 9 = -10 + 9 = -1
\]

2. For \( n = 2 \):
\[
a_2 = -10(2) + 9 = -20 + 9 = -11
\]

3. For \( n = 3 \):
\[
a_3 = -10(3) + 9 = -30 + 9 = -21
\]

4. For \( n = 4 \):
\[
a_4 = -10(4) + 9 = -40 + 9 = -31
\]

Thus, the first four terms of the sequence are:
\[
-1, -11, -21, -31
\]