Question

Show that a1,a2,..........an.........form an AP Where an is defined as below:
(i) an = 9-5n

Answer 1

Given an=9-5n
so a1=9-5(1)
        =4
a2=9-5(2)
    =9-10
=  -1
a3=9-5(3)
    = -6

here common difference (d)=a2-a1= -1 -4=-5 
and a3-a2= -6+1
                 = -5
here a2-a1= -5 and a3-a2=-5
as they have the same common difference, they form a.p.

Answer 2

Answer:

an =9-5n

Step-by-step explanation:

let n be 1 ,2,3, to find the value of an

now by putting these values of n in equation u will get c.d

if the common diff. will be the same

this means that this equation will form an

a.p

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