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India Pre-Regional Mathematical Olympiad
2017 India PRMO
11
2017 preRMO p11, f(x) = sin (x/3)+ cos (3x/10), f(n\pi +x)= f(x)
2017 preRMO p11, f(x) = sin (x/3)+ cos (3x/10), f(n\pi +x)= f(x)
Source:
August 9, 2019
trigonometry
periodic function
minimum
Problem Statement
Let
f
(
x
)
=
sin
x
3
+
cos
3
x
10
f(x) = \sin \frac{x}{3}+ \cos \frac{3x}{10}
f
(
x
)
=
sin
3
x
+
cos
10
3
x
for all real
x
x
x
. Find the least natural number
n
n
n
such that
f
(
n
π
+
x
)
=
f
(
x
)
f(n\pi + x)= f(x)
f
(
nπ
+
x
)
=
f
(
x
)
for all real
x
x
x
.
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