巧用克鲁金定理

A Wise Application of Guldin Theorem

巧妙地运用克鲁金定理，仅用代数方法就解决了一些积分问题。笔者还从克鲁金定理出发，导出了库斯科夫公式，并举出其应用实例。

This paper shows a short cut in solving some integral problems simply by algebraic methods as a wise application of Guldin Theorem. Moreover, it deduces Kyskoff FOrmula directly from Guldin Theorem, and presents some typical examples using the formula.