(Q29).Which of the following are G.P. ? If they are G.P, write three more terms,
(viii)
1
√2
, -2,
8
√2
, ......
Given: t
1
=
1
√
, t
2
= -
, t
3
=
8
√
, ......
t
2
t
1
=
-
1
√
= -
√2
t
3
t
2
=
√
×
-1
= -
√2
∴ r =
t
2
t
1
=
t
3
t
2
= ......... = -
√2
So
1
√2
, -2,
8
√2
, ..... forms a G.P.
where a =
1
√
and r = -
√2
a
n
= a.r
n-1
a
4
=
1
√
× (-
√2)
3
=
-
×
√2
√
= -
a
5
=
1
√
× (-
√2)
4
=
×
×
√
=
√2
a
6
=
1
√
× (-
√2)
5
=
-
×
×
× √2
√
= -
Clear