Question

8.Form an A.P. if it is given that a2=13 and a4=3

Answer 1

Answer:

hope you got your answer

Answer 2

Answer:

a2 = a + d

13 = a + d--------------(1)

a4 = a + 3d

3 = a + 3d-------------(2)

Subract (2) from (1).

13 = a + d

- 3 = a + 3d

_______________________

10 = 0 + ( - 2d )

-2d = 10

-d = 10/2

-d = 5

d = - 5

Put value of d in (1).

13 = a + d

13 = a + ( - 5 )

13 = a - 5

13 + 5 = a

a = 18

a = 18

a2 = 13 ( given )

a3 = a + 2d

= 18 + 2 ( - 5 )

= 18 - 10

= 8

a4 = 3 ( given )

therefore A.P. is 18 , 13 , 8 , 3 , .......