两角和与差的三角公式是三角函数中最基本、最重要的公式,是高考考查的热点之一.其内涵是“揭示同名不同角的三角函数的运算规律”.应用公式求值、化简及恒等式的证明时要善于观察差异,寻找联系,实现转化,在此基础上要注意过好“四关”,下面就近年的高考题进行举例说明. Two-corner and difference triangle formula is the most basic and important formula in trigonometric function. It is one of the hottest points in the college entrance examination. Its connotation is “the law of revealing the trigonometric functions of different angles of the same name”. When proving Jane and identities, one must be good at observing differences, looking for connections, and achieving transformation. On this basis, we must pay attention to the “four levels”. Here are some examples of recent college entrance examination problems.