Question

Can anyone derive me the formula for the nth term from the Last , of A.P?

Answer 1

You want to derive the formula for the nth term of an A.P?

Answer 2

kk..

Answer 3

Let the first term be a1
and the common difference be d
now second term will be
a2=a1+d
third term will be
a3=a1+d+d=a1+2d
Do you get this part?

Answer 4

yes..

Answer 5

Now if we go on like that,
4th term is
\[a_4=a_1+3d\]
Hence nth term will be
\[a_n=a_1+(n-1)d\]
Do you understand this?

Answer 6

yes..and thank u

Answer 7

one question..why do we add 1 on last step

Answer 8

because thee are n terms and before we have n-1 terms

Answer 9

it goes on decreasing such as n, n-1, n-2...

Answer 10

I don't get you, where do you have doubt?

Answer 11

an=a1+(n−1)d, y there is 1

Answer 12

you mean the 1 in n-1?

Answer 13

yes.

Answer 14

for seond term a2, we have d or 1d
for third term a3, we have 2 d
In the formula we have d times ( one no. less than the term no. )
That's why for n we have 1 less than n i.e n-1

Answer 15

kkk

Answer 16

Do you understand?

Answer 17

yes