How do I find the nth term of a sequence?

For any sequence where there is a common difference (it increases or decreases with the same amount, n, each time) you can find the nth term using the formula: dn+(a-d)"a" is the value of the first term in the sequence"d" is the common difference between the termsTo find the nth term you find the values of "a" and "d" and stick them in the formula, dn+(a-d)For example: Find the nth term of this sequence: 3,7,11,15The first term is 3, so a=3The common difference is 4 (as it increases by 4 each time), so d=4By using the formula we get, 4n+(3-4), which is equal to 4n-1We can check this works by subbing in values of n into the formula and you will see that it is correct. 

LM
Answered by Laura M. Maths tutor

30401 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Kieran, Jermaine and Chris play football. Kieran has scored 8 more goals than Chris. Jermaine has scored 5 more goals than Kieran. Altogether they have scored 72 goals. How many goals did Jermaine score?


a). Solve x-4=13, b). solve 7y=35 c). solve 3w-9=27


The perimeter of a right-angled triangle is 72 cm. The lengths of its sides are in the ratio 3 : 4 : 5. Work out the area of the triangle.


A is the point with coordinates (5, 9) B is the point with coordinates (d, 15) The gradient of the line AB is 3 Work out the value of d.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning