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Mathematics
Mathematics
Problem
If
f
(
x
)
f(x)
f
(
x
)
is given by,
f
(
x
)
=
(
cos
x
+
i
sin
x
)
(
cos
3
x
+
i
sin
3
x
)
…
(
cos
(
2
n
−
1
)
x
+
i
sin
(
2
n
−
1
)
x
)
f(x) = (\cos x + i \sin x)(\cos 3x + i \sin 3x) \dots (\cos (2n-1)x + i \sin (2n-1)x)
f
(
x
)
=
(
cos
x
+
i
sin
x
)
(
cos
3
x
+
i
sin
3
x
)
…
(
cos
(
2
n
−
1
)
x
+
i
sin
(
2
n
−
1
)
x
)
, then
f
′
′
(
x
)
f''(x)
f
′′
(
x
)
is equal to a.
n
3
f
(
x
)
n^3 f(x)
n
3
f
(
x
)
b.
−
n
4
f
(
x
)
-n^4 f(x)
−
n
4
f
(
x
)
c.
−
n
2
f
(
x
)
-n^2 f(x)
−
n
2
f
(
x
)
d.
n
4
f
(
x
)
n^4 f(x)
n
4
f
(
x
)
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