9.
已知复数\(z_{1}=\sin x+λi,z_{2}=(\sin x+ \sqrt {3}\cos x)-i(λ,x∈R,i\)为虚数单位\()\).
\((1)\)若\(2z_{1}=i⋅z_{2}\),且\(x∈(0, \dfrac {π}{2})\),求\(x\)与\(λ\)的值;
\((2)\)设复数\(z_{1}\),\(z_{2}\)在复平面上对应的向量分别为\( \overrightarrow{OZ_{1}}, \overrightarrow{OZ_{2}}\),且\( \overrightarrow{OZ_{1}}⊥ \overrightarrow{OZ_{2}}\),\(λ=f(x)\),求\(f(x)\)的最小正周期和单调递减区间.