2.
如图,在\({\triangle }{ABC}\)中,\({AB}{=}2{,}\cos B{=}\dfrac{1}{3}\),点\(D\)在线段\(BC\)上.
![](https://www.ebk.net.cn/tikuimages/2/2018/500/shoutiniao54/eb08d19fc57de1f419a7a526dbc45019.png)
\((1)\)若\({∠}{ADC}{=}\dfrac{3}{4}\pi\),求\(AD\)的长;
\((2)\)若\({BD}{=}2{DC}{,}{\triangle }{ABC}\)的面积为\(\dfrac{4}{3}\sqrt{2}\),求\(\dfrac{\sin{∠}{BAD}}{\sin{∠}{CAD}}\)的值.