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1987 IberoAmerican
2
Find arctan r + arctan s +arctan t
Find arctan r + arctan s +arctan t
Source: IberoAmerican 1987 Q5
November 12, 2010
algebra unsolved
algebra
Problem Statement
Let
r
,
s
,
t
r,s,t
r
,
s
,
t
be the roots of the equation
x
(
x
−
2
)
(
3
x
−
7
)
=
2
x(x-2)(3x-7)=2
x
(
x
−
2
)
(
3
x
−
7
)
=
2
. Show that
r
,
s
,
t
r,s,t
r
,
s
,
t
are real and positive and determine
arctan
r
+
arctan
s
+
arctan
t
\arctan r+\arctan s +\arctan t
arctan
r
+
arctan
s
+
arctan
t
.
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