Question

Shows that each of the following sequences is an A.p and hence find the first 5 terms

3n+4,14-4n,4n-2. Solve it

Answer 1

in general for AP the form is:

Xn = a + d(n-1)

Now look at 3n + 4
Xn = 4 + 3n
let a = 4
let d = 3
Xm = 4 + 3 (m-1)
where m = n+1
m = 1 to 5
4, 7 , 10 , 13 , 16

then 14 - 4 n
again
a = 14
d = -4
m = n+1
Xm = 14 - 4(m-1)
etc