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Mathematics
Mathematics
Problem
Let
f
(
x
)
=
cos
x
f(x)=\cos x
f
(
x
)
=
cos
x
. What is the smallest positive length
L
L
L
such that the average value of
f
f
f
on
[
0
,
L
]
[0,L]
[
0
,
L
]
is
0
0
0
? a)
2
π
2\pi
2
π
b)
π
2
\dfrac{\pi}{2}
2
π
c)
π
\pi
π
d)
3
π
2
\dfrac{3\pi}{2}
2
3
π
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