Question

vn is the nth term of the sequence 15, 13, 11, 9,
(i) Write down an expression, in terms of n, for vn.
(ii) wn is the nth term of another sequence that is obtained by multiplying un by vn.
Given that wn = 17 + kn – 6n2, find k

Answer 1

Step-by-step explanation:

let's see

it's easy to say the Vn gonna be a+(n-1)d

vn = 15+ (n-1)(-2) = 17-2n

let's assume un = p+nq

is another ap such that it's multiplication

(nth term multiplication) with vn gives new sequence wn which is 17 + kn - 6n^2

that is 17 + kn - 6n^2 = (p+nq)(17-2n)

compare constant, coffi. of n and n2 both sides

you will get simple relations and can solve for K

easy..