共50条信息
\((1)\)已知\(\cos \beta =-\dfrac{3}{5}\)，且\(\beta \)为第二象限角，求\(\sin \beta \)的值；
\((2)\)已知\(\dfrac{\tan \alpha }{\tan \alpha -6}=-1,\)求值：\(\dfrac{2\cos \alpha -3\sin \alpha }{3\cos \alpha +4\sin \alpha }.\)
若\(\sin α > 0\)，且\(\tan α < 0\)，则角\(α\)的终边位于 ( )
已知\(\alpha \)为锐角，\(\cos \alpha =\dfrac{\sqrt{5}}{5}\)，则\(\tan \left( \alpha -\dfrac{\pi }{4} \right)=\)( )
若\(\sin \alpha < 0\)且\(\tan \alpha > 0\)是，则\(\alpha \)是 \((\) \()\)
进入组卷