“新教材”在我校已试行了近两年,有很多新意,抽取其中一点细细品味,引发思考,很有价值.1　问题的展示“新教材”———人教版全日制普通高中教科书(试验修订本·必修)《数学》第一册(下)第42页正文如下:“我们已经学习了和(差)角公式,还掌握了和角公式与差角公式可以互相化归. The “new textbook” has been tried out in our school for the past two years. It has a lot of new ideas, and it is worthwhile to extract one of the details. This leads to great value. 1 The “New Textbook” of the problem is displayed --- Full-time normal high school education The text of the Textbook (Test Revision, Compulsory) “Mathematics” Book One (Part Two) is as follows: “We have studied the sum (difference) angle formula, and we also learned that the angle formula and the difference angle formula can be interpolated.