MathDB
Today's calculation of Integral 168

Source: Nagasaki university entrance exam 1980

January 15, 2007
calculusintegrationtrigonometrycalculus computations

Problem Statement

Prove that n=11n+11n1xsinπxdx\sum_{n=1}^{\infty}\int_{\frac{1}{n+1}}^{\frac{1}{n}}{\left|\frac{1}{x}\sin \frac{\pi}{x}\right| dx} diverge for x>0.x>0.