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证明(三角函数)

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/09 14:31:38
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解题思路: (a^2-b^2)^2=[(a+b)(a-b)]^2=16tan^2(A)sin^2(A) 16ab=16[tan^2(A)-sin^2(A)] 要证(a2-b2)2=16ab成立 需证tan^2(A)sin^2(A)=tan^2(A)-sin^2(A) 即证tan^2(A)sin^2(A)-tan^2(A)=-sin^2(A) 即证-tan^2(A)[1-sin^2(A)]=-sin^2(A) 即证-sin^2(A)=-sin^2(A) 显然-sin^2(A)=-sin^2(A)成立 ∴(a2-b2)2=16ab成立.
解题过程:
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最终答案:略