优优班--学霸训练营 > 知识点挑题
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            • 1.
              已知\(f(x)=\sin (x- \dfrac {π}{3})-1\),则\(f(x)\)的最小正周期是\((\)  \()\)
              A.\(2π\)
              B.\(π\)
              C.\(3π\)
              D.\(4π\)
            • 2.
              函数\(f(x)=2\sin x\cos x+ \sqrt {3}\cos 2x\)的周期为\((\)  \()\)
              A.\(T=2π\)
              B.\(T= \dfrac {π}{2}\)
              C.\(T=π\)
              D.\(T=4π\)
            • 3.

              已知\(\Delta A\),\(B\),\(C\)的对边分别为\(a\),\(b\),\(c\),若\({\cos A}=\dfrac{4}{5}\),\(\cos C=\dfrac{12}{13}\),\(a=1\),则\(b=\)

              A.\(2\)
              B.\(\dfrac{56}{21}\)
              C.\(\dfrac{21}{13}\)
              D.\(\dfrac{56}{39}\)
            • 4.
              已知函数\(f(x)= \begin{cases} \overset{x+1,0\leqslant x\leqslant 1}{ \dfrac {1}{2}\sin ( \dfrac {π}{4}x)+ \dfrac {3}{2},1 < x\leqslant 4}\end{cases}\),若不等式\(f^{2}(x)-af(x)+2 < 0\)在\(x∈[0,4]\)上恒成立,则实数\(a\)取值范围是\((\)  \()\)
              A.\(a > 2 \sqrt {2}\)
              B.\(2 \sqrt {2} < a < 3\)
              C.\(a > 3\)
              D.\(3 < a < 2 \sqrt {3}\)
            • 5.
              已知\(a\),\(b\),\(c\)为\(\triangle ABC\)的三个内角\(A\),\(B\),\(C\)的对边,向量\( \overrightarrow{m}=( \sqrt {3},-1)\),\( \overrightarrow{n}=(\cos A,\sin A).\)若\( \overrightarrow{m}⊥ \overrightarrow{n}\),且\(α\cos B+b\cos A=c\sin C\),则角\(A\),\(B\)的大小分别为\((\)  \()\)
              A.\( \dfrac {π}{6}\),\( \dfrac {π}{3}\)
              B.\( \dfrac {2π}{3}\),\( \dfrac {π}{6}\)
              C.\( \dfrac {π}{3}\),\( \dfrac {π}{6}\)
              D.\( \dfrac {π}{3}\),\( \dfrac {π}{3}\)
            • 6.
              \(f(x)=3\tan x\)的最小正周期为\((\)  \()\)
              A.\(3π\)
              B.\(2π\)
              C.\(π\)
              D.\( \dfrac {π}{3}\)
            • 7.

              设\(a\),\(b\),\(c\)为\(\vartriangle ABC\)的三个内角\(A\),\(B\),\(C\)的对边,\( \overrightarrow{m}=\left( \sqrt{3},1\right), \overrightarrow{n}=\left(\cos A,\sin A\right) \),若\(\overrightarrow{m}\bot \overrightarrow{n}\),且\(a\cos B+b\cos A=c\sin C\),则角\(A\),\(B\)的大小分别为\((\) \()\)

              A.\( \dfrac{π}{6}, \dfrac{π}{3} \)
              B.\( \dfrac{2π}{3}, \dfrac{π}{6} \)
              C.\( \dfrac{π}{3}, \dfrac{π}{6} \)
              D.\( \dfrac{π}{3}, \dfrac{π}{3} \)
            • 8.

              已知等差数列\(\{a_{n}\}\)的公差\(d∈(0,1)\),且\(\dfrac{{{\sin }^{2}}{{a}_{3}}-{{\sin }^{2}}{{a}_{7}}}{\sin ({{a}_{3}}+{{a}_{7}})}=-1\),当\(n=10\)时,数列\(\{a_{n}\}\)的前\(n\)项和\(S_{n}\)取得最小值,则首项\(a_{1}\)的取值范围是

              A.\((-\dfrac{5\pi }{8},-\dfrac{9\pi }{16})\)
              B.\([-\dfrac{5\pi }{8},-\dfrac{9\pi }{16}]\)
              C.\((-\dfrac{5\pi }{4},-\dfrac{9\pi }{8})\)
              D.\([-\dfrac{5\pi }{4},-\dfrac{9\pi }{8}]\)
            • 9. 函数\(f(x)=2\sin x\cos x\cos 2x\)的最小正周期为\((\)  \()\)
              A.\(2π\)
              B.\(π\)
              C.\( \dfrac {π}{2}\)
              D.\( \dfrac {π}{4}\)
            • 10. 对任意的实数α、β,下列等式恒成立的是(  )
              A.2sinα•cosβ=sin(α+β)+sin(α-β)
              B.2cosα•sinβ=sin(α+β)+cos(α-β)
              C.
              D.
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