# How do you find n in a series?

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## How do you find n in a series?

All you need to do is plug the given values into the formula tn = a + (n – 1) d and solve for n, which is the number of terms. Note that tn is the last number in the sequence, a is the first term in the sequence, and d is the common difference.

**How do you find the sum of n terms of a series?**

The formula to find the sum of n terms in AP is Sn = n/2 (2a+(n−1)d), in which a = first term, n = number of terms, and d = common difference between consecutive terms.

### What does it mean to find the sum?

sum Add to list Share. When you determine the sum, you add up all the numbers. When you sum something up, you focus on all of its important points. The word sum can also refer to a certain amount of money.

**How do you find the sum of a series?**

To ﬁnd the sum of this series, we need to work out the partial sums. For this particular series, the best way to do this is to split each individual term into two parts: 1 k(k +1) = k +1−k k(k +1) = k +1 k(k +1) − k k(k +1) = 1 k − 1 k +1 .

## Can N(a1+an)/2 be used to find the sum of squared terms?

The formula n (a1+an)/2 can only be used to find the sum of an arithmetic series with n terms. Notice here that a1 is the first term of the series, and an is the last term. Hence, it cannot be applied to find the sum of squared terms. (6 votes)

**How do you find the remainder of a series?**

Now, notice that the first series (the n n terms that we’ve stripped out) is nothing more than the partial sum sn s n. The second series on the right (the one starting at i = n+1 i = n + 1) is called the remainder and denoted by Rn R n.

### How do you find the k-th term of a series?

We write the capital Greek letter sigma, and then the rule for the k-th term. Below the sigma we write ‘k = 1’. Above the sigma we write the value of k for the last term in the sum, which in this case is 10. 2k +1 = 3+5+7+…+21, and in this case the sum of the series is equal to 120.