Find nth Term of Sequence: n2-2

Thread starter Gringo123
Start date Apr 22, 2010
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In summary, the formula for finding the nth term of an arithmetic sequence is a<sub>n</sub> = a<sub>1</sub> + (n-1)d, and for non-arithmetic sequences, a specific formula must be derived. To find a missing term in a sequence, plug in the given values for the first term and common difference into the nth term formula. However, the nth term formula can only be used for arithmetic sequences and not other types of sequences.

Apr 22, 2010

Gringo123

I'd just like to make sure that I understand this question:

"The nth tern of a sequence is n² - 2. Find the value of the 20th term of the sequence."

Is the question asking me to find the value of the equation if n = 20? (In which case the answer would be 20 x 20 - 2 = 398)

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Apr 22, 2010

Mentallic

Homework Helper

Exactly, it's as simple as that

FAQ: Find nth Term of Sequence: n2-2

What is the formula for finding the nth term of a sequence?

The formula for finding the nth term of a sequence is: a_n = a₁ + (n-1)d, where a_n is the nth term, a₁ is the first term, and d is the common difference between each term.

How do you find the nth term of a sequence if it is not arithmetic?

If a sequence is not arithmetic, you cannot use the formula a_n = a₁ + (n-1)d. Instead, you will need to examine the pattern of the sequence and come up with a specific formula for it. For example, the sequence 1, 4, 9, 16, 25... is the square numbers, so the formula for the nth term would be a_n = n².

3. What is the sequence for the formula n2-2?

The sequence for the formula n²-2 is: -1, 2, 7, 14, 23, 34...

4. How can I use the nth term formula to find a missing term in a sequence?

To find a missing term in a sequence, you can use the nth term formula to plug in the given values for the first term and common difference, and then solve for the missing term. For example, if the sequence is 3, 6, 12, 24..., and you need to find the 5th term, you can use the formula a₅ = a₁ + (n-1)d and plug in a₁=3, n=5, and d=6 to get a₅ = 3 + (5-1)6 = 27. Therefore, the 5th term in the sequence is 27.

5. Can the nth term formula be used for any type of sequence?

No, the nth term formula can only be used for arithmetic sequences, where each term is found by adding or subtracting a constant value. For other types of sequences, such as geometric or quadratic sequences, a different formula must be used to find the nth term.