老师们常有这个体会:尽管在教正切函数这一节时,教师一再强调要注意正切函数定义域的限制,但是学生在解题时,却还是常常忽视这种限制,致使解答或不全面,或不严密,甚至产生错误的答案。例如学生在解三角函数有关问题的时候,由于忽视这种限制所产生的种种错误,归纳起来就有许多种。现列举几例以供今后解正切函数有关问题时参考。 Teachers often have this experience: Although in teaching this section of the tangent function, teachers have repeatedly stressed the need to pay attention to the limits of the tangent function definition domain, but students often ignore this restriction when solving problems, resulting in incomplete or incomplete answers. Or not closely, even producing the wrong answer. For example, when students solve problems related to trigonometric functions, there are many kinds of errors that can be summed up by ignoring the various errors caused by such restrictions. Here are a few examples for future reference when solving problems related to tangent functions.