完全平方公式是进行代数运算与变形、解一元二次方程、解二次函数有关问题的重要的知识基础.这个知识点重点是对完全平方公式的熟记及应用.难点是对公式特征的理解(如对公式中积的一次项系数的理解).同学们在学习中常见错误有:(1)难于跳出原有的定式思维,典型错误如(a±b)~2=a~2±b~2;(错因:在公式(ab)~2=a~2b~2的基础上类推,随意“创造”)(2)混淆公式(a+b)~2=a~2+2ab+b~2与(a-b)~2= The complete square formula is an important knowledge base for algebraic operations and deformation, solving quadratic equations and solving quadratic functions.The emphasis of this knowledge point is the memorization and application of complete square formulas.The difficulty is the comprehension of formula features (Such as the formula of the product of the first term coefficient of understanding.) Students in learning common mistakes are: (1) difficult to jump out of the original fixed thinking, typical errors such as (a ± b) ~ 2 = a ~ 2 ± b ~ 2; (The wrong reason: based on the formula (ab) ~ 2 = a ~ 2b ~ 2 analogy, random “create ”) (2) confusion formula + b ~ 2 and (ab) ~ 2 =