Question

In an A.P,if d= -2 Tn=0,then find the value of a

Answer 1

Tn = a +(n-1)d
O = a +(-1)-2
O = a + 3
Therefore,
a = -3

Answer 2

If d = -2
An = 0

An = a + ( n - 1 ) × d

0 = a + ( n - 1 ) × -2

-a = -2n + 2

- a = - ( 2n - 2 )

cancel the signs

a = 2n - 2