化简:[tan(45°+A)/(1-tan²(45°+A)]×[sinAcosA÷(1-2sin²A]

来源:学生作业学帮网 编辑:学帮网 时间:2024/05/31 23:34:51

化简:[tan(45°+A)/(1-tan²(45°+A)]×[sinAcosA÷(1-2sin²A]

:[tan(45°+A)/(1-tan²(45°+A)]×[sinAcosA÷(1-2sin²A]
=1/2*[2tan(45°+A)/(1-tan²(45°+A)]×1/2[2sinAcosA÷(1-2sin²A]
=1/2tan(90°+2A)*1/2tan2A
=1/4cot2A*tan2A
=1/4