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Question
Mathematics
One value of α for which the coefficients of the middle terms in the expansion of (1+α x)4 and (1-α x)6 are equal, is (-3/10) . Other value of ' α ' is
Q. One value of
α
for which the coefficients of the middle terms in the expansion of
(
1
+
αx
)
4
and
(
1
−
αx
)
6
are equal, is
10
−
3
.
Other value of '
α
' is
1914
251
Binomial Theorem
Report Error
A
0
B
1
C
2
D
3
Solution:
In the expansion of
(
1
+
αx
)
4
Middle term
=
4
C
2
(
αx
)
2
=
6
α
2
x
2
In the expansion of
(
1
−
αx
)
6
Middle term
=
6
C
3
(
−
αx
)
3
=
−
20
α
3
x
3
It is given that
Coefficient of the middle term in
(
1
+
αx
)
4
=
Coefficient of the middle term in
(
1
−
αx
)
6
⇒
6
α
2
=
−
20
α
3
⇒
α
=
0
,
α
=
−
10
3