\((I)\)如图,过圆\(O\)外一点\(P\)作圆\(O\)的切线\(PA\),切点为\(A\),连接\(OP\)与圆\(O\)交于点\(C\),过点\(C\)作\(AP\)的垂线,垂足为\(D.\)若\(PA=2\sqrt{5}\),\(PC∶PO=1∶3\),求\(CD\)的长.
\((II)\)已知矩阵\(A=\begin{bmatrix} 2 & 1 \\ 3 & 2 \\ \end{bmatrix}\),列向量\(X=\begin{bmatrix} x \\ y \\ \end{bmatrix}\),\(B=\begin{bmatrix} 4 \\ 7 \\ \end{bmatrix}\),若\(AX=B\),请直接写出\(A^{-1}\),并求出\(X\).
\((III)\)在平面直角坐标系中,以原点\(O\)为极点,\(x\)轴的正半轴为极轴,建立极坐标系\(.\)已知圆\(ρ=4\sin \left( \theta{+}\dfrac{\pi}{6} \right)\)被射线\(θ=θ_{0}\left( \rho{\geqslant }0\mathrm{{,}}\theta_{0}\mathrm{{为常数}}\mathrm{{,}}\mathrm{{且}}\theta_{0}\mathrm{{∈}}\left( 0\mathrm{{,}}\dfrac{\pi}{2} \right) \right)\)所截得的弦长为\(2\sqrt{3}\),求\(θ_{0}\)的值.
\((IV)\)已知\(x > 0\),\(y > 0\),且\(2x+y=6\),求\(4x^{2}+y^{2}\)的最小值.