How do you find the fourth term of an arithmetic sequence?

To find the 1st term, put n = 1 into the formula, to find the 4th term, replace the n’s by 4’s: 4th term = 2 × 4 = 8.

How do you find the 10th term?

To find the 10th term we would follow the formula for the sequence but substitute 10 instead of ‘n’; to find the 50th term we would substitute 50 instead of n. To find the first term we substitute n = 1 into the nth term.

What is the formula in finding the first term of an arithmetic sequence?

Given an arithmetic sequence with the first term a1 and the common difference d , the nth (or general) term is given by an=a1+(n−1)d . Example 1: Find the 27th term of the arithmetic sequence 5,8,11,54,… . a8=60 and a12=48 .

How do you find the 125th term of an arithmetic sequence?

This arithmetic sequence has the first term a1= 4, and a common difference of −5. Since we want to find the 125th term, the “n” value would be n = 125. The following are the known values we will plug into the formula: Example 3: If one term in the arithmetic sequence is a21 = –17 and the common difference is d = –3.

How to apply the arithmetic sequence formula?

Examples of How to Apply the Arithmetic Sequence Formula. Example 1: Find the 35 th term in the arithmetic sequence 3, 9, 15, 21, … There are three things needed in order to find the 35 th term using the formula: the first term ( {a_1}) the common difference between consecutive terms (d) and the term position (n )

How do you find the first term of an arithmetic progression?

The formula for finding n t h term of an arithmetic progression is a n = a 1 + ( n − 1) d , where a 1 is the first term and d is the common difference. The formulas for the sum of first n numbers are S n = n 2 ( 2 a 1 + ( n − 1) d) and S n = n 2 ( a 1 + a n) .

What is the term position in the arithmetic sequence?

The term position is just the n=35 n = 35. Therefore, the known values that we will substitute in the arithmetic formula are Example 2: Find the 125 th term in the arithmetic sequence 4, −1, −6, −11, … = 4, and a common difference of −5.