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\(A\),\(B\),\(C\)的对边分别是\(a\),\(b\),\(c\),且满足\(\cos 3A-\cos 2B=2\cos (\dfrac{\pi }{6}-A)\cdot \cos (\dfrac{\pi }{6}+A)\).
\((1)\)求角\(B\)的值;
\((2)\)若\(b=\sqrt{3}\),且\(b\leqslant a\),求\(a-\dfrac{1}{2}c\)的取值范围.
函数\(f\left(x\right)={\cos }^{2}x-2{\cos }^{2} \dfrac{x}{2} \)的最小值为
设\(P\)为圆\(x^{2}+y^{2}=2\)外一点,过\(P\)作圆的两条切线,切点分别为\(M\),\(N\),若\(\tan ∠MPN=\dfrac{4}{3}\),则\(P\)的轨迹方程是________.
已知\(\sin \alpha -\cos \alpha =\dfrac{4}{3}\),则\(\sin 2\alpha =(\) \()\)
进入组卷