在利用两角和与差的三角函数公式进行化简、求值与证明的题型中,常要根据函数名与角度的差异进行角度变换,若将已知三角函数值或相关等式中的角称为条件角,而将待求的目标函数中的角称为目标角,则这两种角何时用哪个角表示另一个角在不同的题型中是 In the problem of simplifying, evaluating and proving by using trigonometric formulas of two angles and difference, it is often necessary to change the angle according to the difference between the function name and the angle. If the known trigonometric function value or the correlation equation Angle is called the conditional angle, and the corner in the objective function to be sought is called the target angle, which corner of the two corners is used to represent the other corner in different question types