Write a formuls for the general term(nth term) of the arithmetic sequence. Do not use a recursion formula. Then use the formula for A to the n to find the indicated term of the sequence
find a11: 12, 10, 8,...
The first term is a1
Every subsequent term is a constant number d greater than the one before so it goes:
a1
a2 = a1 + d
a3 = a1 + 2d
a4 = a1 + 3d
a5 = a1 + 4d
.....
an = a1 + (n-1)d
for example
a14 = a1 + 13*d
makes no sense that's how i was doing it and I came up with 3.5
a11 = 12 + 10(.8444) = 3.5
however the answers to choose from are
.32
-8
-10
.34
Write a formula for the sequence below. Then find a11
{-2, 5, 12, 19, …}
To find the general term (nth term) of an arithmetic sequence, you need to know the first term (a), the common difference (d), and the position of the term you want to find (n).
In this case, the given arithmetic sequence is 12, 10, 8, ...
To determine the general term, you can observe that the common difference (d) is -2. Each term decreases by 2.
Using this information, we can apply the formula for the nth term of an arithmetic sequence:
an = a1 + (n-1)d
Now, substitute the given values:
a1 = 12 (the first term)
d = -2 (the common difference)
n = 11 (the position of the term you want to find)
an = 12 + (11-1)(-2)
an = 12 + 10*(-2)
an = 12 - 20
an = -8
Therefore, the 11th term of the given arithmetic sequence is -8.