Find the nth term of the sequence 7,11,15,19...

The nth term is a formula that allows us to find the value of a term in a sequence given its position in the sequence, whether this is the second term (n=2) or the millionth (n=1000000). In the above sequence, there is a difference of four between each term: 11-7=4, 15-11=4, etc. This means that the nth term is going to look something like 4n+6, or 4n-3, but we need to be sure of the number we are adding or subtracting at the end. The first term (n=1) is seven. So we know that 4(1) + something = 74(1)=4x1=44+something=7and subtracting 4 from both sides gives us 3. So the nth term is 4n+3. To check our answer, we can check another term. The fourth term (n=4) is 19, so putting n=4 in our formula should give 19.fourth term = 4(4)+3=16+3=19, which is what we wanted, so we can be sure that the nth term is indeed 4n+3.

JB

Related Maths GCSE answers

All answers ▸

Prove that one interior angle of a a regular octagon = 135 degrees


Lottie has a bag of applies. She gives half of them to Fred. Fred eats two and then has four left. How many apples did Lottie have at the start?


What is the quadratic formula and how do I use it?


Five numbers have a mean of 9.4 . Four of the numbers are 3, 5, 10 and 12. Work out the range of the five numbers. ( 4 marks )