\tan\left(x^{2} y^{2}\right)\cdot\cos\left(x y\right)=\cos\left(x^{2} y^{2}\right)

请输入您的数学问题…… \tan\left(x^{2} y^{2}\right)\cdot\cos\left(x y\right)=\cos\left(x^{2} y^{2}\right)

问题

tan (x^{2} y^{2}) \cdot cos (x y) = cos (x^{2} y^{2})

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