设\(z\)是虚数,\(ω=z+\dfrac{1}{z}\)是实数,且\(-1 < ω < 2\)
\((1)\)求\(|z|\)的值及\(z\)的实部的取值范围;
\((2)\)设\(u=\dfrac{1-z}{1+z} \),求证:\(u\)为纯虚数;
\((3)\)求\(ω-u^{2}\)的最小值
进入组卷