MathDB
Problems
Contests
National and Regional Contests
Japan Contests
Today's Calculation Of Integral
2005 Today's Calculation Of Integral
86
Today's calculation of Integral 86
Today's calculation of Integral 86
Source: 1984 Jyosai University Entrance exam
September 27, 2005
calculus
integration
trigonometry
calculus computations
Problem Statement
Prove
[
∫
π
∞
cos
x
x
d
x
]
2
<
1
π
2
\left[\int_\pi^\infty \frac{\cos x}{x}\ dx\right]^2< \frac{1}{{\pi}^2}
[
∫
π
∞
x
cos
x
d
x
]
2
<
π
2
1
Back to Problems
View on AoPS