共50条信息
已知\(\sin \left( \left. \dfrac{π}{4}-x \right. \right)= \dfrac{3}{5}\),则\(\sin 2x\)的值为\((\) \()\)
在\(\triangle ABC\)中,角\(A\),\(B\),\(C\)所对的边分别为\(a\),\(b\),\(c\),若\({\,\!}_{b}^{c} < \cos A\),则\(\triangle ABC\)为
已知\({\sin }\left( \alpha +\dfrac{\pi }{6} \right)=\dfrac{2\sqrt{5}}{5}\),则\({\cos }\left( \dfrac{\pi }{3}-\alpha \right)=\)( )
若\(f(\cos x)=\cos 3x\),那么\(f(\sin 70^{\circ})\)的值为( )
\(\sin {{210}^{\circ }}\) \(=\)( )
\( \dfrac{2\cos 80^{\circ}+\cos 160^{\circ}}{\cos 70^{\circ}}\)的值是( )
\(\sin (-600^{\circ}) =\)
进入组卷