Problem 19

Question

Given the general term of each sequence, find each of the following. \(a_{n}=10-n^{2}\) a) the first term of the sequence b) the 6 th term c) \(a_{20}\)

Step-by-Step Solution

Verified
Answer
a) \(a_1 = 9\) b) \(a_6 = -26\) c) \(a_{20} = -390\)
1Step 1: Find the first term (a)
To find the first term of the sequence, we plug in n=1 into the general term: \(a_1 = 10 - 1^2 = 10 - 1 = 9\) So, the first term of the sequence is 9.
2Step 2: Find the sixth term (b)
To find the sixth term of the sequence, we plug in n=6 into the general term: \(a_6 = 10 - 6^2 = 10 - 36 = -26\) So, the sixth term of the sequence is -26.
3Step 3: Find the twentieth term (c)
To find the twentieth term of the sequence, we plug in n=20 into the general term: \(a_{20} = 10 - 20^2 = 10 - 400 = -390\) So, the twentieth term of the sequence is -390.