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Mathematics
If (1 + x)n =C0 + C1x + C2x2 + ..... + Cn xn, then the value of C0 + 2C1 + 3C2 +....+ (n + 1) Cn will be
Q. If
(
1
+
x
)
n
=
C
0
+
C
1
x
+
C
2
x
2
+
.....
+
C
n
x
n
, then the value of
C
0
+
2
C
1
+
3
C
2
+
....
+
(
n
+
1
)
C
n
will be
6394
190
COMEDK
COMEDK 2006
Binomial Theorem
Report Error
A
(
n
+
2
)
2
n
−
1
38%
B
(
n
+
1
)
2
n
0%
C
(
n
+
1
)
2
n
−
1
62%
D
(
n
+
2
)
2
n
0%
Solution:
Since,
x
(
1
+
x
)
n
=
x
C
0
+
C
1
x
2
+
C
2
x
3
+
....
+
C
n
x
n
+
1
On differentiating w.r.t. x, we get
(
1
+
x
)
n
+
n
x
(
1
+
x
)
n
−
1
=
C
0
+
2
C
1
x
+
3
C
2
x
2
+
...
+
(
n
+
1
)
C
n
x
n
Put x = 1, we get
C
0
+
2
C
1
+
3
C
2
+
...
+
(
n
+
1
)
C
n
=
2
n
+
n
2
n
−
1
=
2
n
−
1
(
n
+
2
)