三、等价解的确定性从等价性的反面来看,让我们提出质疑:三角方程的解发生异变后,是否存在不等价的解?可以断言,任何三角方程如果有解并且发生异变,则所有不同形式的解一定等价,即不存在异变的不等价解,故能肯定, Third, the certainty of the equivalent solution From the negative side of equivalence, let us ask questions: After the solution of the trigonometric equation has been changed, is there an unequal solution? It can be asserted that any trigonometric equation if there is solution and the occurrence In case of change, all different forms of solutions are equivalent, that is, there is no inequivalent inequality solution, so it can be affirmed,