用解析法求作两回转体相贯线

利用解析法建立与回转体对应的曲面方程，进而推导出曲面间的交线（相贯线）曲线方程，并利用描点法作出两曲面立体的相贯线投影，用解析法取代作图法不仅使作图过程变为求点坐标的过程，而且可准确求出相贯线上极限位置点的坐标，使作出的相贯线投影更准确。

Drawing Projections of Intersection of Two Cycloidal Surfaces by Analytics

The author introduced a method employing the analytics that contructed the equations of the cycloidal surfaces. Moreover it constructed the equation of the intersection of two cycloidal surfaces by the deductive, and drawing the projections by joining the points. The analytics method replaced that drawing auxiliary planes. It changed the course from drawing auxiliary planes to calculating the coordinates of points. Using the method, you may exactly obtain the coordinates of any points on the intersection and the coordinate of the limiting point. The limiting point could not exactly be obtained using drawing auxiliary planes. The method made the projections of intersection more exactly.