所谓隐含条件就是指那些从显现的已知条件中推导出来的条件。如果在求解时,只注意了显现条件,而忽略了对显现的已知条件作更深层次的分析,就会导致求解失去准确性。挖掘隐含条件,它能使角及三角函数值的范围得到准确的限制,简化或避免复杂的变形与讨论,使问题正确且简洁获解。故挖掘隐含条件 Implicit conditions refer to those derived from the known conditions of appearance. If we only pay attention to the conditions of the solution while neglecting the deeper analysis of the known conditions, we will lose the accuracy of the solution. Mining implicit conditions, it can make the range of angular and trigonometric functions accurate limits, simplify or avoid complex deformation and discussion, so that the problem is correct and concise solution. Therefore, mining the implied conditions