本刊 2 0 0 3年第 6期《一道正切函数题的错解辨析》分析了一道与函数的周期性有关的问题 .原题　设函数y =10tan[( 2k - 1) x5] (k∈N+ ) ,当x在任意两个连续整数间 (包括整数本身 )变化时 ,至少两次失去意义 ,求k的最小正整数值 .辨析中只考虑函数在x∈ [0 ,1]两次失去意义 , The issue of “analysis of a tangent function problem with a solution to a tangent function problem” in 2003 was analyzed in relation to the periodicity of the function. The original problem is set to function y = 10tan[(2k - 1) x 5] (k∈ N+ ), when x changes between any two consecutive integers (including the integer itself), loses meaning at least twice, finds the smallest positive integer value of k. In the differentiation, only the function is lost twice in x∈ [0,1]. Meaning ,