二次根式是初中代数的重要内容，不少同学由于没有掌握好二次根式的意义，常出现以下错解现象．一、概念不清例１已知a是实数，a２√是二次根式吗？错解：因a２√＝｜a｜，而｜a｜不是二次根式，故a２√不是二次根式．分析：对形如a√（a≥０）的式子叫二次根式的理解应注意两 The secondary root formula is an important content of junior high school algebra, and many students often do not have the following misconceptions because they do not grasp the significance of the secondary root formula. First, the concept is not clear Example 1 is known that a is a real number, a2 is a secondary root type? Misunderstanding: Because a2√=|a|, and |a| is not a secondary root, a2√ is not a secondary root. Analysis: The understanding of the form of a quadratic root-like equation such as a√ (a ≥ 0) should pay attention to two