共50条信息
如图所示,\(A,B,C,D\)为平面四边形\(ABCD\)的四个内角\(.\)若\(\angle A+\angle C=18{{0}^{\circ }}\),\(AB=6\),\(BC=3\),\(CD=4\),\(AD=5\),则\(\tan \dfrac{A}{2}+\tan \dfrac{B}{2}+\tan \dfrac{C}{2}+\tan \dfrac{D}{2}=\)__________
若\(\cos \alpha =-\dfrac{4}{5}\),\(\alpha \)是第三象限的角,则\(\dfrac{1+\tan \dfrac{\alpha }{2}}{1-\tan \dfrac{\alpha }{2}}=\)_____________.
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