Question

find the first four terms of an A.P ,whose first term is -2 and common difference is -2

Answer 1

hi mehak

here is your answer

Given as

a = -2 ( first term )

d = -2 ( Common difference)

As we know that

an = a + ( n - 1 ) d

As first term is - 2, to calculate 2nd term we will put n = 2

a2 = -2 + ( 2 - 1 ) -2
= -4

Now n = 3 to calculate third term

a3 = -2 + ( 3 -1 ) -2
= -6

Now n =4 to calculate fourth term

a4 = -2 + ( 4 -1 ) -2
= -8

Hence the first four term of AP is

-2 , -4, -6 and - 8

hope it helps
#jerri

Answer 2

first term = -2
difference= -2
according to general formula of an a.p,
$a2 = a + d \\ a3 = a2 + d \\ a4 = a3 + d \\ so \\ a2 = - 2 + ( - 2) = - 4 \\ a3 = - 4 + ( -2) = - 6 \\ a4 = - 6 + ( - 2) = - 8 \\ \: the \:first \: four \: terms \: of \: ap \: whose \: first \: term \: is \: - 2 \: nd \: common \: difference - 2 is \\ - 2 \: - 4 \: - 6 \: - 8 \: .......$