5.
在平面直角坐标系\(xoy\)中,曲线\(C_{1}\)的参数方程为\( \begin{cases} \overset{x=a\cos \phi }{y=b\sin \phi }\end{cases}(a > b > 0,ϕ\)为参数\()\),在以\(O\)为极点,\(x\)轴的正半轴为极轴的极坐标系中,曲线\(C_{2}\)是圆心在极轴上,且经过极点的圆\(.\)已知曲线\(C_{1}\)上的点\(M(1, \dfrac { \sqrt {3}}{2})\)对应的参数\(ϕ= \dfrac {π}{3}\),射线\(θ= \dfrac {π}{3}\)与曲线\(C_{2}\)交于点\(D(1, \dfrac {π}{3})\).
\((\)Ⅰ\()\)求曲线\(C_{1}\),\(C_{2}\)的方程;
\((\)Ⅱ\()\)若点\(A(ρ_{1},θ)\),\(B(ρ_{2},θ+ \dfrac {π}{2})\)在曲线\(C_{1}\)上,求\( \dfrac {1}{ ρ_{ 1 }^{ 2 }}+ \dfrac {1}{ ρ_{ 2 }^{ 2 }}\)的值.