球与多面体的切接问题,一种是内切,一种是外接.解题时要认真分析图形,明确切点与接点的位置,作出合适的截面图,在平面图形中进行研究,下面举例加以分析.例1已知球的半径为R,球内接一个正四棱柱,棱柱底面边长与高为何值时,它的侧面积最大?解图1为轴截面,令棱柱的高为h,底面边长为a,侧面积为S, Ball and polyhedron cut the problem, one is the cut, one is the external. Problem-solving should carefully analyze the graphics, the cut-off point and the location of a clear point to make a suitable cross-sectional figure in the plane graph to study the following examples Example 1 Known ball radius R, the ball is connected to a quadrangular prism, the bottom edge of the prism length and height of the value of the maximum, its side area is the largest solution Figure 1 is the axial section, so that the height of the prism h, Bottom length is a, side area is S,