已知向量\(\overset{→}{m}=(2,\sin α), \overset{→}{n}=(\cos α,-1) \)，其中\(\alpha{∈}(0{,}\dfrac{\pi}{2})\)，且\(\overset{→}{m}⊥ \overset{→}{n} \)．
\((1)\)求\(\sin 2\alpha\)和\(\cos 2\alpha\)的值；
\((2)\)若\(\sin(\alpha{-}\beta){=}\dfrac{\sqrt{10}}{10}\)，且\(\beta{∈}(0{,}\dfrac{\pi}{2})\)，求角\(\beta\)．