Here are the 1st five terms of a number sequence.
3 7 11 15 16

a) work out the 8th term of the number sequence.
b) write down an expression, in terms of n, for the nth term of the number sequence.

see explanation

Step-by-step explanation:

Note there is a common difference d between consecutive terms, that is

d = 7 - 3 = 11 - 7 = 15 - 11 = 19 - 15 = 4, thus sequence is

3, 7, 11, 15, 19, 23, 27, 31 ← with 8 th term = 31

The sequence is arithmetic with n th term

= a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a ₁ = 3 and d = 4, thus

= 3 + 4(n - 1) = 3 + 4n - 4 = 4n - 1

cosine

step-by-step explanation: